35-105mm f/3. is easily the best for versatility and overall utility. at the wide angle range the 20-35mm is up there with the best but expect to pay for it. i got a 24-35mm for $60 and it is great. a little bit more distortion than the 24mm f/2.8 but very sharp for a zoom. although the 35-70 is nice enough to start, a 50mm plus two legs does the same thing. imo a zoom needs to add something a little extra to be worth it so the wide L series or the slightl longer 35-105 would be my only recommendations. otherwise just stick with the 50