Your TV will have either composite video or RCA jacks built in unless it is VERY old (ie from the 70’s) – so you don’t need to buy anything unless it IS that old – then you need an RF converter. The RCA cables comes with the Wii.
Actually, they took out some features with the latest consoles! Mine is older, and can (in theory) use GameCube games. We don’t have any of those… BUT we have 3 “Active” games (Active Life Explorer, Active Outdoor Adventure, and Active Extreme Challenge) that use a floormat that plugs into the GameCube controller input. Those games wouldn’t work with a new console.
It probably isn’t a big deal, as it isn’t easy to find those kids “Active” games so much (We bought the one new, with the mat 2 Christmases ago… then the 2nd used (no mat) last Christmas, and the 3rd used when we saw it at a used game place). But it is something to be aware of.
I don’t think the newest consoles have any features we don’t already have… that I know of anyway!