Trypticon and Scorponok are the best known. Metrotitan is a little lesser-known repaint of Metroplex from the Japanese release of Micromasters. There's also Tidal Wave, who is a Titan in some continuities.
Metrotitan and Black Zarak, pretty much. I think that Gigastorm sort of counts but I dunno about that...
If you want to go by the new IDW continuity Vigilem played a role in the Ascenticon/Rise plot. Not official Decepticon but if you wanna go faction affiliation. Theres also Necrotitan
And it'll go on quarter price when it won't sell, as opposed to the half price most of the others have.
Grand Maximus.(Though limited,let's make it a mass release by supporting the plastic crack they sell )
Honestly it shocks me they even MAKE Titans anymore Despite what they may think, there are NOT enough weebs in the Western market to shill half those characters to. ESPECIALLY at that price point. Wait, wasn't that a TT Mall exclusive?
I honestly feel like Scorponok is gonna be the last one. It's why Commander class is happening now. We got the big city boys done (plus a bonus pair of Combiners), and besides repaints and super obscure comic book only characters (which I would want, but unil Hasbro puts them in a cartoon or movie, they won't have the necessary meda saturation to sell a 200 dollar toy) Japan media exclusive characters are a bit easier to swallow at deluxe/Voyager/leader prices. But Titans are already a gamble as it is. Especially with toys r us dead and the retail presence of Titans with them. Consider that for a minute, Scorponok, Omega Supreme, and Predaking were all online exclusives. If not in name, then definitely in practice. Oh, there are enough weebs in the west, problem is that they've already spent their 200 bucks on big tiddie anime girl statues, inuyasha wall scrolls (kids still watch the inuyasha right?) and Loot boxes in whatever Fate Mobile Game has them additcted this week.
You did, as a footnote to an off base and incorrect statement. A TT Mall exclusive is not "mass retail" by any measure.