Walk around prime lens for crop sensor

It's tough to recommend a lens for someone without knowing lots about them and their style. So I'll just list some options and their +/-

Sigma 18-35mm f/1.8 - great lens in terms of image quality - like someone else said, it's like a bag full of primes in one zoom lens (otherwise I wouldn't recommend a zoom when someone asks about a prime). Better at the wider than the long end though. Also, sharpness falls off after about f/4 so if you are going to shoot closer to the long end (sounds like you might) and/or stopped down, it may not be the best choice given the cost, size, and weight.

Canon EF 24mm f/2.8 IS USM - small, lightweight, optically very good, has IS! I had this lens and sold it. I just wasn't impressed with the IQ difference between it and the 18-55mm IS STM. There's only 2/3 of a stop difference between the two at similar focal lengths (23mm on the zoom wide open is f/3.5) and while the prime is sharper, the performance difference and minimal use it got didn't justify keeping it around (for me).

Canon EF-S 24mm f/2.8 STM - small - like... pancake small, inexpensive, and if it performs as the MTF charts suggest it should, optically great. Also, I read an article or watched a video (can't remember which) where the author said when considering a new prime lens, cut your current focal length on half (or double it) to get a substantially different angle of view. So you have a 50, half would be 25 and the 24 is close enough. Downside is, it's pretty wide if you want a "standard" lens. Might not be what you're looking for. Also, it's designed for crop sensor cameras so should you decide to move to FF, it's incompatible.

Canon EF 28mm f/1.8 - older, inexpensive, not overly sharp, especially wide open. Not a bad choice bit there might be better options. Angle of view is great for a "standard" angle of view.

Canon EF 28mm f/2.8 IS USM - better than one equal to the one above in every way except max aperture and cost.

Sigma 30mm f/1.4 ART - could be a great choice and highly versatile. Faster than anything else on this list. Sharp, not large, and not insanely expensive. For me, it would be between this and...

Canon EF 35mm f/2 IS USM - I own this one and love it! Use it quite often on my 70D and on my 6D occasionally. Nothing negative to say about it.

There's also the Canon 35mm f/2 - it's an older lens and was replaced by the lens above. It's still good but compared to the newest lenses, it's not great.

For the Canon IS options, consider buying directly from Canon's refurbished store. If you wait for a 15-20% off sale, you can get them for well under what they're worth.

If you find yourself deciding between the Sigma 30 and Canon 35IS, just ask yourself if f/1.4 or IS is more important, and that'll make your decision.

Hope this helps!