I am trying to figure out which ROTF figure before the nest wave Gears Thrust Swerve Breakaway Blaze Master
Thrust. Breakaway looks like crap, Gears isn't a great choice of mold for the name, Swerve's colour is poor, Blaze Master is alright but nothing special.
I say Thrust as well. He's better than Breakaway, the original version of the mold. Gears is a meh repaint of a TF1 toy. I don't know if you already have Sideswipe, but Swerve is not great for a repaint, with the dull red. I've also heard some shaky things about Blazemaster, and he doesn't seem like a very solid figure. So I'd say go with Thrust.
While I don't have Thrust, I think you should get him over Breakaway. He'll go good with Dirge if you plan to get him too.
Mindwipe >_> Seriously, love this figure, best in the line. Uh...of the ones listed though, honestly if you have to get one of those (and only one of those) go for Gears (I like the mold, though not the colors on this version) or Thrust.
Vote for Swerve. The new head suits the body more. It also has way more weapons than thrust. With the grenade launcher and the scissor swords versus thrust's automatic but kind of small wrist gun.
I really like the Breakaway/Thrust mold, but prefer Thrust's colours. I would recommend both happily. Swerve is a great mold, spoiled somewhat by a rather odd, dull pale pinkish red. Haven't opened my Blazemaster yet so perhaps that tells you something about how uninspiring he is. Gears is a good figure too, but like people have said, he is Gears in name only. To summarise, go with Thrust or Breakaway.
I actually like Breakaway better than Thrust, but Thrust is objectively better. One of the reasons why is that he's one of the pieces in a complete TF:Movie Seekers collection. Also, he pairs really well with ROTF Dirge, particularly in alt mode.
I actully was planing to paint breakaway's cyan spots with silver metallic and breakaway's becoming kind of rare around her. So it will be him or Thrust.