G1 Astrotrain because it is one of the few that I still have left (that isn't broken) from when I was a kid.
Either TFCC Timelines Astrotrain because it was the first one I really made an effort to go and get, or g1 blurr because I had always wanted one and found one complete in my parents basement from my childhood that had been sitting in a dusty cardboard box for probably over 20 years unbeknownst to me. Neither are anywhere near what I would think of as the "best," but they're my two favorites. The best that I own? Probably either leader starscream or cybertron primus.
Damn, tough question. I don't really have a #1 for official products...City Commander is my overall #1, and the one toy I'd hold onto if I had to sell everything else. However, I think for official I can probably narrow it down to a few...dunno which I'd choose though. Alternators Mirage, Classics Mirage, Classics Inferno, Tokyo Toy Show Black Prime and Dark Skyfire, and ROTF Powered Prime are all figures I absolutely never intend to sell though, unless dire circumstances arose. Those are all toys I'd want to hand down to my kids at some point if they ever got into collecting.
Mmm. Definitely RotF Buster Prime. He's the best mold of the character we have, and with a bitchin' paint job to boot. I just wish I had some way to liberate him from his cardboard prison.
I'd have to say T2 Optimus Minor. I know a lot of people would do a spit-take but I don't have very many figures especially rare or expensive big ones. I just think O.Minor is a really cool figure with a cool design and he is my oldest, not counting G1 Micromaster Tankor that got released in Cybertron/Universe. FE Starscream is a close second for his excellent engineering and the fact that I have the Takara version. (A little bit better than Hasbro I assume)
RotF Leader Prime is right up there for me, but honestly, if I could only keep one TF, it would be Galaxy Force Noisemaze. For me, at least, it's pretty much the perfect Deluxe-sized toy - flying alt mode, great articulation and conversion, lots of character, unobtrusive yet fun gimmick, plenty of fan-mode potential...it's endless fun.
Official figs I'd have to say MP Grimlock but after recently getting classics Wheeljack he is right up there too. I reckon I'm gonna really like Hound too when I pick him up later today.
I'll always have the softest spot for my G2 Optimus Prime with black trailer. I have 2; one still sitting nicely in the box signed by Peter Cullen, and the other loose ... signed by Peter Cullen. I just love that figure. So many childhood memories.
i'd have to say movie legends barricade. i love small toys and for a toy of its class it has amazing articulation.
I'd have to say 25th Optimus Prime. The original was my first TF as a kid and my 25th is the one that got me back into collecting. Love that guy.