Aye, the recharging battery pack things are well worth a look, typical rechargable batteries don't seem to last very long in the Wii controllers, but the rechargable pack and charger I got for £10 seem to do quite well. You can get ones that charge one or two controllers, and from the plug or from USB on the back of the Wii.
Games wise I'd recommend:
Metroid Prime (based on the rest of the series)
Zelda (just awesome if you like adventure games)
Godfather (If you don't mind ps2-esque graphics)
Mario Strikers
Resident Evil 4
Super Paper Mario