All my gear is standardized to AA or CR123 batteries. I buy each in bulk (Energizer Lithiums and Surefire CR123s) and that's all I use. With a 15+ year storage life, it's not a big deal to buy 'em in bulk.

I've never had good luck with rechargeable batteries and I find that, if my batteries do go dead, it's typically in the middle of me doing something somewhat important. Therefore, I'm not going to have the opportunity to recharge. Instead I'll just replace and get right back to whatever I was doing.