I have a canon xti and i only have the kit lens (18-55mm). i'm leaving out of country- korea, Philippines, maybe japan or china. beautiful cities/scenary etc. so i want a decent lens to carry around and take all the pics i could.

what would be best for this? a lot of city shooting, mtn. scenary etc., (mainly outdoor shooting). I'm looking to spend around $3-500. im relatively new to this hobby so i don't know what's out.

Canon EF 50mm F1.8 II SLR Lens -52mm

Canon 28-135 f/3.5-5.6 USM IS
Canon EF 70-200mm f/4L USM (no IS)

I'm thinking about getting the 50mm ($70 + f1.8, can't beat it) and one of the two above or alike. Any other recommendations?