I would be all over a symbiote. Okay, technically the symbiote would be all over me, but it's the same thing really.
I wouldn't do any superheroism or supervillainy either, I'd just roll with the enhanced physical abilities.
By the way, you should probably specify it if you're talking about the symbiotes from the Marvel universe. Most of what I said applies anyway, even if it's a completely different kind of symbiote - whatever benefits it offers, I'm going to vote yes on the symbiosis unless there are drawbacks that outweigh the benefits.