Since it's hard for me to pick favorites overall, I'll have to list them by weight class.
Lightweights:
5. The Big B. It reminds me of a machine from TLC's Robotica called Viper, which was basically a 6wd wedge. It was Viper, or specifically Viper Revision 2, that first inspired me to get serious about building a combat robot although I never actually had the chance until recently.
4. ChiaBot. It's a shrub on wheels. 'Nuff said.
3. Dr. Inferno Jr. Does this one really need explaining?
2. She fights like a girl. Bad News with looks.
1. Ziggo. Admit it. Sometimes you don't have to sacrifice looks for capabilities.
Honorable Mention: Stewbot. Are you ready to LEGO? Honestly, those guys were both brave and foolish to enter a LEGO Mindstorms robot into battlebots, but then again they were the only ones to do that. Points for originality.
Middleweights:
5. ChiaBot (with the spinning blade). It's a shrub on wheels. With a spinning blade.
4. Deadblow. Grant Imahara's robot as looks as good as it fights. And we know why Deadblow was ranked #2 in the middleweight class.
3. El Diablo. Treads suck as a motive platform, but they look awesome. Of course, that spinning drum looks evil too.
2. Eraser. It's a giant eraser.
1. Root Canal. Tube-frame rollcage, omnidirectional drive, and a saw. Innovative and just plain awesome.
Honorable Mention: Palindrome 3.3. It's unique, and that's saying a lot in the sport.
Heavyweights:
5. Mauler 51-50. It's a robot that you should fear... if it doesn't spin itself to pieces, that is... I love a robot that combines looks with (at least potential) effectiveness.
4. Nasty Overbite. Also know as Jawbreaker, This clamp not only looks awesome, but it's surprisingly effective. It didn't get very far in battlebots, but it was a finalist in TLC's Robotica.
3. Panic Attack. Hey look... it's a former Robot Wars champion! Painting a robot well is one thing, but keeping that paint looking good is much harder. What's their secret?
2. Son of Whyachi. Just take one look at the first robot in my showcase and you'll know I love horizontal spinners with freakin' huge hammers.
1. Warhead. Ok. I kinda cheated here. Warhead isn't on the list. It was still a Battlebots competitor, and almost did to Battlebots what its predecessor did to Robot Wars. Speaking of its predecessor...
Honorable Mention: Razer. Another former Robot Wars champion. You really can't deny that beak/claw/fang looks lethal.
Super Heavyweights:
5. The Brainsters of Triskellian. You're going to have to see this machine yourselves. It's the only Segway balanced combat robot I've seen - ever.
4. Chin-Killa. You cannot fight the power of THE CHIN!!! Jay Leno's personal Ultraheavyweight looks great.
3. Diesector. See Dr. Inferno Jr. Also see Ziggo.
2. Mechadon. See Dr. Inferno Jr. Do not see Ziggo.
1. Snake. Not as well known as Setrakian's mechanical spider, but honestly I think a robot like Snake, which is able to move without any sort of wheels or legs at all, is actually a more advanced design than a robot that uses six legs to move.
Honorable Mention: The Judge. ORDER IN THE COURT! OBJECTION OVERRULED!!! Also, am I the only person who thinks that "Team Mechanicus" is a reference to Warhammer 40,000?