The 18-55 kit lens that came with my 550D got old in 2 days. Ugh. So I've been looking for some better glass to use as a do-it-all everyday lens. I have a budget of $1000. I'll be doing indoor events including sports as well as outdoor nature shots and vacation photos. For that purpose I have a couple candidates. EF-S 17-55mm f/2.8 IS USM EF-S 15-85mm f/3.5-5.6 IS USM (plus a 85mm f/1.8) EF 24-105mm f/4L IS USM EF 24-70mm f/2.8L USM They all have top-notch image quality. The differences between them are so mild that I'm really not concerned about IQ in this dilemma anymore. The first two choices are obviously the cheaper ones, with the 15-85mm being ~$200 cheaper than the 17-55mm. I really like the fast aperture of the 17-55mm, but I feel like I will be limited by the comparatively small zoom range which isn't much of an improvement from the 18-55mm. Also, the 15-85mm has a 4-stop IS while the 17-55mm is the older 3-stop version. I'm also worried that the 17-55mm will have seal problems that many people are having. But the huge disadvantage for the 15-85mm is the variable slow aperture which hinders its lowlight performance. Then the prime lens combo comes to play. Being faster than any zoom lens, the 85mm prime should add some lowlight capabilities to the setup, but I feel like I might be hindered by the lack of IS and/or zoom with the prime, and switching lenses might be too much of a hassle for fast-paced events like sports. Then I considered some better lenses that perhaps are a bit out of my range. The most obvious choice was the venerable 24-70mm. Fast aperture with the perfect focal length! But the problem is that I might miss some of the wide angles, it weighs more than the camera, and it lacks IS. Plus, it's $1200 used (but an excellent investment!). Or I could go with the 24-105mm f/4L IS USM. Albeit slower than the 17-55mm and the 24-70mm, it's still faster than the 15-85mm at most focal lengths, has a greater reach on a crop body, etc. but again, I might miss the wide angles and it weighs a lot. It's also on the upper end of the cost spectrum. I also feel like the f/4 might not be enough for indoor sports photography. In the event that I someday end up getting a full-frame camera, I guess the EF lenses would be a more worthy investment, but I'm really not concerned about that right now. I have really put thought into this dilemma but I still can't decide on which setup to go with! Could someone please give me advice on which lens to go for? Thanks!