This is what I use:

• PowerEx 2700 mAH AAs I have not formally measured their self-discharge rate, which would be easy to do with a good charger that displays info, but I'll try to remember to set aside a pair for a month and do so. I have no self-discharge problems with them.
• LaCrosse BC-900 : Superb charger which can now be found online for $40. Don't get the upgraded model which requires something like 100 button presses every time you use it. The BC900 does everything you would likely need.
• Maha MH-C401FS: Great tiny charger. Not as capable as the La Crosse but portable and easy to travel with.

Finally, I don't have these but you can check out Maha's new 2100 mAh Immedion AA. They claim 85% capacity after one year, but my batteries never sit around that long. I have alkalines and lithiums for storage, which do a lot better than 85%. (Main reason to get something like this might be if you want rechargeables for emergency storage, the cells may die if you let them completely discharge; this seems like it might avoid that problem.)

One last note: Good chargers will let you set the charging current. Lower current = less heat = longer battery life. I usually use 200-400mA, which takes a few hours to charge however many I have in the charger. You can set a much larger current, but the batteries will overheat and suffer in the long run.