There are the A-frame hardsides, like Beer Belly mentioned. Aliner, Chalet, the Rockwood/Flagstaff/Coachmen models, and the Jayco/Starcraft models. There's Hi-Lo and TrailManor, not sure if they're currently in production. Then there's a 'sort of' popup made in Quebec Canada, the Alto by Safari Condo; it is hinged at the front so from there to the back raises up via electric switch. I know of no others in production right now.
About 10 years ago, Fleetwood made the Highlander Tacoma. The side walls hinged at the bottoms and flipped vertical after you raised the roof. These even had an indoor wet bath, I believe.
https://www.uclookup.com/detail/2008-Fleetwood-Highlander-Tacoma-Hard-Side-Pop-up_182008026987.html I recall being interested in them back then.