My least favorite Transformer is Cybertron Backstop. On the 4th of July I took him out with a few fireworks. So, what's your least favorite Transformer? http://http://www.tfw2005.com/resources/attachment.php?do=fullview&attachmentid=7321
I wouldn't say I really hate any of the TF's I own, though I would probably say my least favorite is probably Movie Deluxe Barricade or Jazz. Barricade has the dumb arm gimmick, a fiddly transformation, messed up hands, and I'm not a fan of how he looks hollow if you want to display Frenzy seperately. Jazz has messed up arms, looks chunky when he should be the sleekest looking movie bot next to Sideswipe, and a weird weapon. I don't outright hate either, but both can use major upgrades. I can't wait to get HA Barricade, and I pray that Movie Jazz, despite being dead, will get a new and improved toy at some point.
2007 Movie Voyager Megatron, I could rant for hours about him I've said it before, Runabout would have a good home in my collection
Any G1 pretender, I never bought any as I thought they looked so dumb. As for modern TFs, the Animated combo Safeguard is horrible.
it has to be tfu legends leo prime. i hate it with a passion. i do have razorclaw, it was part of the 5-pack nyways.