All the stuff about auto-power-on and coming back to a particular channel is good advice, but when it comes to quality I've found my El Cheapo Apex 27 inch works great. The video quality is just fine on all my games -- I even play vector games and don't have any serious problems. Yes, a real arcade monitor or a PC monitor would be even better, but at this size I'd pay a heckuva lot of more money. 95% of what I run on the TV looks fantastic.
The price is right -- I got mine on Black Friday for $130. I think they list for around $150, and you can often find them on sale for less. Best quality TV? No way. Good enough for most MAME? You bet.