You'll get some proper recommendations, but I'll mention that I have a very cheap no brand thing that cost under $50 at a grocery store. A skeptical, low investment purchase. It's amazing.

No fancy features, the design could clearly be improved, but chuck anything in this small chamber, crank up the timer and delicious food comes out 10mins later. I've gifted nice models to others, without feeling any need to upgrade my own. Maybe when it breaks.

I would suggest sticking with a small one though. Quicker to heat, better circulation etc