What should i buy for my 550d?!

[MLeeK]

When a lens covers a huge amount of zoom like the 18-200 it compromises on quality. There is a lot that goes into making a lens work and focus over the range of the zoom. Hence why prime lenses are the sharpest-there is no compromise. On a HUGE zoom like that there is huge compromise to match it.
They are fair. OK for walk about and better than most cell phones, however I wouldn't put it up against the new iPhone 4s and expect it to perform better.

 

[belial]

isn't it better than having 18-55+55-250 and switching every minute? i mean does 18-55 + 55-250= 18-200 sigma? a walk around lense
that way ill have a 18-200 + 50mm1.8 + kenko extension tube set
soooo?

I personally think having the two lenses is better than one lens to do it all. And you shouldn't be switching lenses every minute. Something I've been doing a lot myself is picking one lens to take with me on photo trips and concentrating on what I can see with that one lens. Youll get more interesting perspectives this way and will be thinking more about what you can do with how you can frame your subject with what you have and less about if you should change lenses or not. For this reason I'm soon upgrading to only prime lenses

 

[mokster]

With my 550d i have these lenses

Tamron 28-75 f2.8 - Awesome lens, highly recomended
Canon 55-250 IS - Surprisingly good lens, need to work at it to get its best results
Canon 50mm f1.8 - Plasticy, cheap but an awesome little prime for the money, love this lens
Canon 70-200mm f4 l USM Non-IS - Wow, just wow this lens is stunning

Leaves a bit of a gap in my camera bag, next lens will either be the sigma 10-20 or the canon f1.8 85mm

Thats whats in my camera bag. Did have the 18-55 kit lens, but that was sold as the tamron will always go on in place of it.