The GameCube's replacement, the Nintendo Wii, can do everything the GameCube could and more. It can handle both GameCube and Wii game discs, plus a selection of classic NES, Super NES, Sega Genesis, Turbografix 16, and Nintendo 64 titles on its pay-per-download Virtual Console. But while the GameCube console itself is defunct, its accessories are not: Most of them work on the Wii, and--because GameCube games and most of the Virtual Console titles can't utilize the standard Wiimote controller--you'll actually need some of them. The Nintendo WaveBird ($35) is one such controller, a wireless GameCube game pad that plugs into the Wii's top controller ports to play older games.
The WaveBird is chunky, but fits comfortably in the hand. The controller weighs just over half a pound, making it heavier than the smaller Mad Catz GameCube MicroCon Wireless Controller, but not uncomfortably so. Since both the WaveBird and the original wired GameCube controller are made by Nintendo, they share the same layout, and their buttons feel almost identical.
The WaveBird communicates with the Wii via a small dongle that plugs into one of the console's four GameCube controller ports. It works fine, but the need to open the cover flap (on the side or the top, depending on whether your Wii is oriented horizontally or vertically) and attach the transceiver does ruin the console's minimalist aesthetic. As with the Wii controllers, the WaveBird utilizes two AA batteries; you'll probably want to invest in a set of third-party rechargeables.
As a wireless controller, the WaveBird can function on 16 different wireless channels. These channels are selected manually through small dials under the game pad and on the wireless receiver. These multiple channels are handy if you're using more than one WaveBird at a time or if you're experiencing interference or controller lag on any single channel.