Sony PlayStation AC Adaptor/Charger (Model CECHZA1)
First, this is NOT a power adapter for your console. It is a standalone device that can be used to plug controllers in and charge them via the USB cables that came with your system. It plugs straight into a wall outlet, and has two USB ports to connect controllers (or other devices, more on that in a second). It also allows you to charge while playing without sitting close to your console or needing a really long USB cable, so long as you have another outlet nearby.
Being a USB charger, it can also be used to juice up headsets, MP3 players, phones, and anything else that charges via USB. It has the added benefit of being the only adapter/device that will charge my Creative Zen MP3 player, which is notoriously stubborn about charging off anything other than a PC or proprietary Creative AC adapter.
It disassembles for easy storage and transportation, and having found it on clearance, it's been a great little find for me.
Nyko Charge Station — Wiimote Charging Dock (Item# 87000-A50)
This cradle can charge two Wii remotes at a time, with the blue/green indicators beneath each one letting you know their charging status. It can be tricky getting the controllers to lean properly on the charging prongs to receive juice; I ended up putting a rubber band around the whole thing to apply more pressure in the desired direction and make sure they charged. The unit has a small footprint as the remotes stand upright with a slight lean while charging, and comes with two rechargeable battery packs.
On the upside, it works. On the downside, charging can be a bit inconsistent, showing a green light (fully charged) but then when testing the controller it only shows up half charged. Also, the batteries seem to lose charge relatively quickly while sitting around doing nothing off the cradle. Not sure why that is.
If you go through a lot of batteries with your Wii remotes, this could be a good alternative if you don't mind giving up the entire remote to charge it every day or two. Otherwise, you may want to try rechargeable AA batteries, or sticking with the tried and true single use batteries if the financial math makes better sense in your situation to do so.