Whoa, great question Andy. I've got a list and a half.
Here it goes.
254 - The Cheesy Poofs
As mentioned before, the poofs rock. I've been a long time admirer of their team (I distinctly remember watching the 2001 SVR webcast, and being amazed at that robot, and the way it was handled). Every interaction I've had with this team since then has been strongly positive, I even got the chance to work with these "greats" in Cleveland 2002. They were one of the easiest teams I've ever worked with.
It'd be sweet to hang out with them for a year, and learn how they work. Hopefully I'd find a way to contribute to their awesome program. Plus, living in San Jose for a year would be a nice change.
111 - Wildstang
The most beautiful, incredible robots in FIRST. Form and function.
Seriously, check out their 2002 entry which did EVERYTHING, or their 1997 entry which defies all expectations, and just keeps getting taller...
I want to learn. Raul, need someone to just sit around doing CAD? I'd enjoy just watching these guys work. I've gotten the chance to hang out with some of their mentors on several occasions, and it's always been a GREAT time. Another team I'd have a ball with, and learn a lot from.
45, 65, 217 - Technokats, Huskie Brigade, Thunderchickens...
Andy Baker, Ken Patton, & Paul Copioli. Between the three of them, they have taught me most of what makes me a halfway decent FIRST Mechanical designer. They have taught me so incredibly much over the years, despite the geographical distance between us. They probably don't even know the impact they've had. I'm glad to call them my friends.
I would love the opportunity to jump onto one of these dynamic teams, and just sit back and learn. I'm sure Andy/Ken/Paul, as well as the other mentors on those teams would be able to teach me a ton about not only robotics, but about being a better mentor. There is nothing quite like having a strong rolemodel to emulate.
234 - Cyber Blue
Another incredible program. Over the past few years I've gotten to know a lot of the mentors from this team, and gotten to see their team in action. They are one of the strongest teams I've seen off the field. On the field, they are a tough competitor, but still not "all they could be". I would love the opportunity to work with them, and maybe help take them to the next level. Watch out for 234 folks, they get stronger every season.
121, 48 - Rhode Warriors, Delphi E.L.I.T.E.
Great people, great robots, great friends of ours. It'd be great fun to go work with them. Both of these teams have proven themselves as tough competitors who take pride in the positive experiences they provide their students. I know I'd have a blast.
Either of you guys need a drivetrain nerd?
20 - The Rocketeers
I'm a Shenendehowa HS Alumnus, it would be incredible to get the opportunity to go, give back to the team that gave so much to me. Plus, my father is still a team 20 mentor, and it'd be fun to work with him on this project. (Hopefully we'd still be speaking to each other by the end of 6 weeks).

These guys are a strong program, that no one knows about. They must have something special going for them if they've stuck it out since 1992....
2892 - Chief-Techno-Thunder-Beatty-Stanger-Poofs
I'm not quite ready to start my own rookie team. I'm not sure if I'm even ready to be the "backbone" mentor for a low-resource team. But, I'd be willing to give it a shot, and work my butt off to be successful.
The name? A homage to those who inspire ME.
Okay... I know I'm a copout listing a whole bunch of teams. Grady asked for "one" team, and I guess now I have to deliver:
71 - "The biggest of the big dogs." Team Hammond
There is a reason these guys have won 4 national championships. I want to learn EXACTLY what it is.
There is no other team in FIRST which has been as successful as these guys, both on and off the field.
Everything I know about them, and every new thing I learn makes me admire them more. Not only do they regularly field the most competitive robot of the year, but they also provide strong positive experiences for their kids, while having a lot of fun.
I'm sold. Sign me up. I'm ready and eager to learn.
You'll just have to forgive me if I routinely zone out during work sessions, admiring your past robots.
(Their 2001 & 2002 entries are ALWAYS on my list of "top robots of all time")
Seriously folks. When I'm trying to show people the excitement of FIRST, I show team videos from these guys (thanks for letting me steal a little of your thunder

). We routinely watch their stuff just to get fired up.
Say the word, and I'll move to Hammond tomorrow.
Overall you see the trend here?
Teams who inspire me, teams who I get along with, teams who I learn from, and teams who I'd have fun with. These are the ones I'd want to be on.
I'm sure there are tons of others out there who fit these criteria. I don't mean to snub anyone, but this is who I came up with.
Ahh well.
I'm on 229 for one more year, then, we'll see what happens.
Until then, watch out. The boys from northern NY are coming back stronger than ever. Our entire team is just rearing to go.
$.02 x 50
John