Alright, after giving some thought as to what I consider "top ten of the decade" and then subsequently procrastinating on taking actual pictures, I've decided to skip photography and just use links.
I've picked these not just for their own sake's, but also to give a sense of the variety of things have bloomed from 2011-2020. If I were just going to list figures that are my favorites if not remarkable in a larger sense, most of Titans Return and Power of Primes would be on here. So, just assume that they are and that we're past having to list the Monsterbots and Decepticon head-target-masters.
In no particular order, here are ten-ish things I like from Hasbro and Takara over the past decade, plus one third party figure:
Springer and
Sandstorm (2013-14)
I think Warcry already noted Sandstorm, but I'll mention them again as a pair. It's not
just that it's the most coherent triple changer mold ever made for the mainline offerings, but that it's also one of the best examples of how thoughtful remolding can yield two figures from the same base that's not even immediately apparent. Extensive retooling has since become the norm, more or less, but usually just for figures with two modes, not three. Titans Return saw the same idea with some of its triple changers (Broadside and Alpha Trion, I think), but no other pair of figures fights the same war on three fronts and
wins like Springer and Sandstorm do.
Steelbane (2017)
A non-entity and a bit of a shelfwarmer, but easily one of my favorite figures. A big part of the appeal is the aesthetic of a medieval knight for the robot mode contrasted with the dragon mode. It's a thematic relationship that works well on paper, and the design itself is neat. Particularly, the dragon mode has a great deal of articulation and expressiveness to it, from being able to fold up its wings to stand on the ground four-legged to being able show mood by rotating its little antlers. It's the kind of figure that really needs a display stand to fully appreciate. Also, I do like how the wings simply do double-duty and are incorporated into the robot mode. All that praise aside, it would really benefit from being a size class larger to give it the part count to fold away and hide some of the glaring bits, namely the robot feet hanging off the neck and tail. Even so, I like it in spite of, or maybe because of, that kind of compromise. It really shows off the compound of ideas that they can do at the deluxe price and size point when they're not trying to adhere to existing design.
Cosmos (2014)
For reasons similar to Steelbane, I think pretty highly of Cosmos. He's made of only two dozen-ish parts, and yet transforms from a cute little flying saucer into a nicely articulated robot. It's the simplicity and efficiency that impresses me the most. He's basically a disc, which is a simple geometric shape, and yet he turns into a very nicely proportioned humanoid while using a small number of parts to do so (just look at other versions of cosmos to see where this can go wrong). They even thought of how to get the engines to make a little jetpack for the robot mode! Anyway, this version of Cosmos has always stuck in my mind not just because of how well it uses the basic shape of a disc, but also the comparative lack of practice they had to build on. Most transformers are either cars, planes, or four legged animals, all of which roughly have the same oblong rectangle shape which isn't too far from the human form. A disc is not as complementary to the challenge, so I like it all the more that it succeeds while being so simple and clean.
Waspinator (2014)
HE IS GREAT AND I LOVE HIM, THE END.
TFC Hercules (2011-2012)
Though completely outdated now (in fact, we have
five six different third party Devastators, plus the official one from Combiner Wars), Hercules needs a mention for just how impactful he's been for the third party market. Before Hercules, third party stuff was limited to add-on kits and small-ish individual figures like the Fansproject Insecticons. What TFC did with Hercules was to expand the third party market boundaries in price, scale of the project, and length of time for completion. With one set of figures, they showed that there was a buying audience for larger, more expensive figures over a fairly lengthy release schedule (roughly ten months for the full set, if I remember right). Considering most of the third party figures now take full advantage of that market territory cleared by Hercules, and I have to give it some kudos even if the figure set itself is quaint and sub-par compared to other combiners (heck, even other Devastators!) since. As such, he's the only figure I can list with confidence as being notable in the last decade while at the same time recommending
not buying today.
Exhaust (2015)
The past decade has seen the explosion of the masterpiece line, so rather than try and list impressive feats of engineering and have them dominate the list, I'll just pick a few that broadly represent the different ways they've struck out into new territory. The first that comes to mind is Exhaust. Not just that it's hilarious (he's a decepticon mobile advertisement for Marlboro cigarettes named Exhaust that's based on a real supercar that was destroyed in a fire.
Ha.), but also because he was (I think?) the first new character invented for the masterpiece line as an excuse to use an old Diaclone deco. Inasmuch, Exhaust was the first of the real oddball masterpiece figures. I appreciate the eclecticism and variety that the MP molds are usually offered in, and Exhaust was the spearhead for that.
Masterpiece Megatron (2017)
For reasons similar to Cosmos, but at the complete opposite end of the spectrum, I'd pick MP Megatron. Handgun Megatrons, practicality of the alternate mode aside, are always interesting engineering challenges. As I said above, most transformers are either cars, plans, or four-legged animals because the rough shape already has loose analogs to the humanoid form. Usually, the designers can take the easy route and have symmetrical robot emerge from that alternate mode (aside from the asymmetrical weirdos like the RID car brothers and lots of the BW figures, which are interesting
because of that weirdness, but anyway). In the case of Megatron, it's an uphill battle from the start as a handgun is not analogous to a humanoid robot to begin with, and on top that he has the asymmetrical challenge of reorienting what becomes the robot's chest from the chamber.
It absolutely shouldn't work, even if they were to use cheating and fake parts (which they didn't!), and yet they pulled it off anyway, and the robot is
great. And it still all starts with sketches with pen and paper. I am in awe, even now. Of course, I can't assign all that praise without acknowledging that transforming it to-and-fro isn't a nightmare, but it's a nightmare that's justified by what it accomplishes, which is the impossible.
Sharkticon Megatron (2014)
Completely different flavor than the above Megatron, the Sharkticon Megatron from Beast Hunters is one of my favorite Megatron figures. I enjoy... its whimsy. It's just so goofy and fun. It's as if a G2 figure had its over-the-top graphic stickers actually
be the alternate mode. Ultra-realistic alternate modes, scale model cars, or strict adherence to animation models can make for interesting engineering challenges, but it's also good to remember that these things can just be good silly fun. Plus I like saying SPACEFISH, which is what it is.
Earthrise Optimus Prime (2020)
A recent figure, but I think it'll end up being regarded as the best mainline G1 Prime figure we're likely to get. It just hits all the right notes, from making an interesting-though-not-convoluted transformation, to a great looking and articulated robot, to a 'complete' truck mode with trailer. It's a minor annoyance that it doesn't have the battle axe or Roller, but whatever. It's been carried over into the Kingdom line without any changes, so that means it'll be on the market shelves for 12 or 18 months, and honestly it deserves to be. He's a banner figure for collectors, kids, and everyone in between.
Studio Series Devastator (2019-2020)
You knew this was coming. He's just so remarkable in ways other combiners aren't. The gorilla robot mode, the asymmetrical combinations, the weird-ass individual robot modes, the span of sizes of the figures... and they pulled it off with only minor compromises (mostly extra parts or visible robot bits). Compare it to any other combiner, and note how ROTF Devastator and the component Constructicons are so far out of the design 'comfort zone' of the G1 template that the subsequent success of the whole party is basically overwhelming.
Movie Masterpiece Optimus Prime (2017)
For reasons of engineering, and for reasons that are personal. The robot mode was designed first with a sense of visual language without much regard for how what part would end up where (drive wheels in the thighs, steering wheels in the ankles, fenders and fuel tanks in the back, etc.). So, having to work backward from the robot into the truck was going to take a lot of percolating. In fact, they pretty much nailed the mechanism in 2009 with the ROTF leader mold, but the masterpiece version is a refinement of that, does away with the few fake parts the previous figure used out of convenience.
And, for me personally, I've spent a lot of time thinking about the movie version of the character, even going so far as to present an essay about him at an academic conference a couple of years ago. I worked how impossible a physical toy of this design should be into the essay itself, and brought him along to sit on my pile of books about populism and film theory as I gave my reading, so yeah... this figure is pretty significant to me.