When I first got my Xbox I picked up a pair of play n' charge kits to deal with battery charging. I found that after a few months neither pack would hold a charge for more than an hour (if that), and out of sheer laziness I ended up leaving the charge kit wire plugged in all the time, essentially giving me wired-wireless controllers. Laziness trumped actually sorting it out however, and I have been putting up with these damned wires for years now. My annoyance level has finally peaked over my laziness level for some reason and I'm sorting this out.
Given the grief I've had with these play 'n charge things I'm not going that route again and am actually thinking about just getting some regular rechargeable AA's and a charger. I've seen Duracell commercials on TV lately for 15 min chargers that might do the job nicely, though I've heard they can ruin a battery over time. That said now that I'm looking into it there are a lot of choices, and some of the newer rechargeables are apparently best for "high drain devices"... not sure if an xbox controller would qualify.
What are you guys using for batteries in your 360 controllers, and how is it working out for you?