Can't say I was that into racing games this gen... until I took a gamble on a Logitech Drive FX (360) for cheap (less than £25 from play at one point).

Was fed up that it didn't handle very well with Burnout Paradise (feedback was pants, had to crash to feel something.. maybe the official wheel is better with that game), but Sega Rally, Midnight Club: LA, Forza 3 and PGR4 are fantastic with it. You can feel the jolt as you change gear and you can keep a pretty sweet line round a corner due to a increased distance from the centre (ie a released state when you let go of the stick it returns to centre) when compared to a stick.

I suppose what I am saying is that even a racer that gets an average score can be transformed with a wheel. Best of all, most of the games above can be had for £10 or less each!