+1 for the eneloops, definately the undisputed champion of rechargables, you do end up spending alot on them though they do recharge more than most.
ive read good reviews about the 7dayshop hybrid rechargables also which are about 1/3 the price but cant comment on them myself.
Ive tried AAA Energiser Lithiums in my LED Lenser H7 and was totally unimpressed. I barely got any life out of them and ended up replacing with GP Recyko+ hybrids which i found were excellent both on price and life.
-P