[elroyie]

I have three lenses now.
Canon 100-400L IS (~160-640 on 20D), it is my tele lens, it is great, I don't have (for now) bad things to tell, the only thing is that it is very expensive lens.
Canon 28-135IS (~45-210 on 20D), it is not a bad lens' it covers a very nice zoom area, and the results are not bad at all, it is not an 'L' lens, but it does the work.
Tokina 20-35 (~32-56 on 20D), it is very surprising lens, the quality is not bad at all, even good (for me), it is my wide lens, it is not wide enough, but I am trying to do the best with this lens until I will have wider lens.

I hope that I gave you an answer, do not hesitate to ask again for more information.

Elroyie