I went from a 550D to a 5D mark 3 (after borrowing my husband's 50D in between). None of these had flip out screens. I much prefer a flip out screen now for when I'm doing macro shots.
It would be good to share what sort of photos you like to take as some will be better at some things e.g. you might want lots of frames per second for action, or good low light capability. Also what is your budget?
Do you already have lenses that you want to keep? Are they EF-S lenses? If they are EF-S then they will only fit the cropped sensor bodies, but if they are EF fit lenses then they will fit any of the cropped or full frame DSLRs. Something to think about in terms of budget if you need to buy new lenses as well.
I'm not familiar with the latest Canons, but the xxD range (70D, 80D and poss. 90D now) has a flip out screen. These have cropped sensors, like the 550D so you could use the same lenses.
A step up from the xxD range is the xD range - 6D, 6Dii, 5D, 5D mark ii, iii or iv which have full frame sensors, or the 7D, 7D mark ii which have cropped sensors. I think the 6Dii might have a flip out screen, but the others don't.
It's worth trying to get to a shop to see if you can try the cameras for size in your hands.