The 11-16 range is bout as wide as you'll get before hitting fisheye. It's very very wide.
On the crop sensor camera, it's still pretty wide, but acts like a 17ish-26ish lens. Keep in mind your 50 is acting like an 80.
What is your lens budget?
I just picked up a used Tamron 17-50 f/2.8 for $350 and a new Rokinon 85mm 1.4 for $270. The Tamron has some rave reviews, some not so good. I'm planning on posting a few test images and videos once I get it in. I'm really excited about the Rokinon. Great for tight shots and portrait photos, the reason it's so cheap is that it's manual focus only. for video though, no problem.
Some other good options (staying under $700 that the 11-16 is priced) would be a Sigma 24-70mm 2.8, a Tamron 28-75mm 2.8 (the sigma is better, but about $200 more), or a Canon 24-70 2,8 L, but tha'ts closer to $1200. Stellar lens though.
What type of video do you do? For film stuff, where you have multiple takes and can set up shots primes are a great way to go. If you REALLY search, you can find a Used canon 28mm 1.8 and a 85mm 1.8 for about $700, or go with the Rokinon for even less. Rokinon also makes a 35mm 1.4 that looks awesome, but it's closer to $500 and near impossible to find used for less.
If you do video or photography for live events, you should really look into a mid range (24-70 or close) zoom with a 2.8 aperture or faster. When something is happening on stage or the groom is about to kiss the bride you can't afford the time it takes to swap lenses.
In video, especially with your crop sensor, you won't be able to use the 70-200 very often unless your trying to hit something from far away. Again, live events when your camera has to be in the back. The long focal lengths multiply shakiness which multiplies rolling shutter too.
Finally, a popular low budget and collector thing to do is go for old 34mm film camera lenses, specifically the M42 screwmount. Super Takumars are awesome, and even cheaper lenses have a special look. You can find a Super Takumar SMC 50mm 1.4 all day long for around $100 (or less if you visit lot's of pawn shops) but other focal lengths are either a lot slower (most 28mm are 2.8) or more rare and therefore more expensive.You already have a 50, not much sense in buying another. These are pure manual focus lenses too.
Hope that broadens your lens horizon and gives you some Ideas! I've been researching like crazy the past week before I bought the two I mentioned earlier. I'm always a little weary about buying non-canon glass, but hopefully the reviews will prove true and they will be stellar. If you're not sure wether or not you want it, try renting first. Or if you need to, buy used. Just make sure you get a good enough deal that you can sell it for the same amount or more if it's a lemon.
