<< Go with Li-ION batteries. Lighter, carry more power per charge (lasts longer), not subject to the memory effect that Ni-MH has. Ni-MH is cheaper than Li-ION though. >>
nickel cadmium batteries have the memory effect, nickel metal hydride does NOT have the problem. i prefer to use Li-ion batteries for big things like camcorders and laptops, and prefer ni-mh for smaller things like my md player, gba, cd player, etc.