Apart from L lenses what is good glass

I find this a very confusing subject. We are always being told to buy the best glass we can but after L glass which lenses stand up to scrutiny ? I have the 100mm L macro and the 70-200 f4L and these take a fair dent out of one's budget I also have the 15-85 kit lens with the 7d and it is generally acknowledged to be a good lens but what other non L lenses are any good and who says so if you get my drift.

The main reason I'm asking this is that I'm looking to buy the Canon 10-22 UWA but some say this is a poor quality lens for a 7d. Again who decides this and as this is the widest for a crop if you want to stay with Canon whats the alternative. I know we all have our favorites but I would be interested to know what people think is good non L glass
Sorry if I've made this complicated but I hope you know what I'm getting at

Cheers all