Well hello all, I'm new here so please don't eat me.

In all seriousness though, I plan on saving roughly around $1000 - $1500 to buy a new lens (or a new set of lens).

What I'm looking for is a walk-around lens/lens combo for my Canon T1i. I shoot landscapes, city street life, portraits, and the occasional sports events. Currently, I have the Canon 18-55mm, 55-250mm, and 50mm 1.8. It's been serving me well for about 2-3years and I have decided it's time to upgrade. I do plan on selling the lenses to help pay for the upgrade though.

I've been planning accordingly and I have come to these combos:

1). Canon 17-55 f/2.8: I really do like the IQ and constant wide aperture at all focal lengths. What's scaring me into no purchasing the lens is the price tag, and I won't be able to upgrade to FF if I wanted to.

2). Canon 17-40mm f/4 L and Canon 70-200mm f/4 L: I like the 17-40mm range for my crop camera, and with the 70-200 I feel like I have a large amount of range covered. A problem with this combo is that it's extremely slow lenses. Both of the lenses are f/4, and I do shoot at night (I like late-night street photography.) Another problem is that I've heard that the 17-40mm isn't considered a good L lens. I've never had experience with it though, so I can't trash talk it. The Canon 70-200mm is really impressive. I had the chance to test this lens and I really like it. A lot. But, like I've stated before, the max aperture of f/4 scares me. And the fact that it does not have IQ also pushes me away from this lens.

3). Canon 15-85mm f/3.5-5.6: Like the 17-55mm, the 15-85 has gotten a lot of praise for having great IQ and a useful crop range. It's been on my watch list for a very long time, but I really feel like I need a fast lens for my night photography shots. That the main reason why I've been avoiding this lens for a while now. Due to the fact that this lens is considered to be both a wide angle and medium zoom, I've decided that if I get this lens, I'd be placing the rest of the money towards a new body (7d most likely)

4) Tamron 17-50mm f/2.8 and Canon 70-200mm f/4 L: I have, however, had the chance to play with the Tamron 17-50mm and I was really impressed at the IQ. Another this that I found attractive about this lens is that really low price tag when compared to Canon's 17-55mm. The real reason why I've been avoiding this lens is the amount of complaints it's received for having such poor Quality Control. The Sigma is worse that both the Tamron and the Canon, therefore ruling it out. Unless some one can prove me wrong.

Those are the 4 combos I've been really considering. I'd like everyone input on these choices. Tell me which ones you guys like and if you can, I'd like to listen to you suggestions about which combos work well for you guys.