You can play most games with the PS3 (using motioninjoy) or X360 controller, but using an actual Wiimote is better with certain games that make heavy use of motion controls. E.g. Zelda Skyward Sword.
For the Wiimote setup, you require:
1. A usb bluetooth dongle that connects to your PC
2. An original Wiimote (not the counterfeit Chinese ones that are sold separately in our local market). Fake ones have snappier buttons. Some shopkeeper should be able to sell you one that comes inside the console bundle. See this link for subtle differences between fake/real wiimotes: Made In China: Fake Wii Remote & Nunchuk
3. Wii Motion Plus add-on. Alternatively, you could just get a wiimote that has it built-in. Newer revisions of the Wii come with such controllers.
For the Wiimote setup, you require:
1. A usb bluetooth dongle that connects to your PC
2. An original Wiimote (not the counterfeit Chinese ones that are sold separately in our local market). Fake ones have snappier buttons. Some shopkeeper should be able to sell you one that comes inside the console bundle. See this link for subtle differences between fake/real wiimotes: Made In China: Fake Wii Remote & Nunchuk
3. Wii Motion Plus add-on. Alternatively, you could just get a wiimote that has it built-in. Newer revisions of the Wii come with such controllers.