I could not figure out how to create a poll without creating a thread first... So, glad you took the first step.
I'd suggest making the poll simple and having the following.
1) 1680x1050 and lower
2) 1920x1080 (16:19) and 1920x1200 (16:10) both combined.
3) 2560x1440 (16:9) and 2560x1600 (16:10) and greater.
4) Other (maybe eye-finity or whatever else here...)
Edit ***
I see that you have already created the poll... I don't want to complain or nitpick, but I feel that many of the users also have older 1280x1024 monitors as well. Probably not the norm anymore, but about 2 years ago that was the dominate resolution. I imagine that there are several users out there that still have not upgraded from those.
Additionally, the size itself is not so important as the resolution, since that is what will make the video card work harder.