Lens recommendation based on current usage

Hi, I'm new here and relatively new in photography; I would like your opinion on which lens I could buy next.

I've been using my canon T4i since 2013, before that i used a couple unremarkable point and shoot cameras.

Trying to learn what i enjoy the most in photography, my original plan was getting an all around lens with the biggest focal range i could find, and use it for a while to see what range I prefer. In my first weeks I sold the kit lens and got a canon 18-200mm IS. After a couple of months I learned some things about balancing aperture and focal distance and tried my luck with a 40mm f2.8 pancake that was replaced later with the newer 24mm f2.8 (both canon).

So my lens experience is only:

• 18-200mm
• 40mm f2.8
• 24mm f2.8

You can see I stayed with cheap lenses with arguable bad image quality. I can't invest in expensive lenses as of now, i consider prices > $600 USD expensive given my current income.

The next (current) part of my plan is to sell the 18-200mm and buy something with better image quality in a focal range better suited for my use. Here's were the data gathered comes in.

I've plotted some stats from my lightroom catalog (2458 photos), shown here is focal distance and aperture graphs. I used JF data plot plugin.

focal distances

aperture

Most of my photos are from trips and vacations, and occasionally a night out with friends. I enjoy mostly landscapes but indoor group shots take a considerable amount of my catalog. Considering this, I've been looking at wide to normal lenses and wide and (or) fast primes.

I'm in Mexico, but can buy from the USA (adorama, B&H or ebay) and don't mind buying used lenses. Specifically I'm currently interested in these:

• Sigma 17-70mm F2.8-4 DC
• Canon 15-85mm F/3.5-5.6
• Canon 10-18mm f/4.5-5.6 IS

I would like to read your opinions and suggestions about which lens would work best for me.

P.D. I apologies for any errors in my writing, English is not my first language.

I just picked up the EFS 15-85mm because I wanted a lens that made my 7D more fun to use as a walk around camera. 15-85mm is a nice range in one lens and I saw it being fun to use and it is! I have the Sigma 18-35 F1.8 which is crazy good but the focal range is too short for walk around use IMO. I am pleasently surprised with the 15-85. It's not as sharp as the Sigma and it exhibits some CA but I can say that so far it takes consistently very good image quality at all focal lengths. I can only see the differences with the Sigma when viewing images at 100%. Slightly less tack sharp on the EFS 15-85 images when viewed at 100%...and some minor visible CA at 100%. Minor enough that to me its not a problem and I will not shy away from using the EFS 15-85 instead for the Sigma 18-35. I will use the Sigma when I need a faster lens or use it like a prime. It's just so much fun to have 24mm to 135mm in one lens with consistently very good image quality.

I also have the EFS 10-18mm. This lens surprised me too. Highly recommended. It's slow but the IS makes up for that big time.

Ron