1) location location location (I mean, you can find the perfect little restaurant somewhere but if it's fucking far away, you're not gonna be going there much are you?)
2) the actual food (you're there to eat, right..)
3) the servis (if that's bad, there's really no point in returning. Lately there's been a trend in Prague of moody waiters, uggh, get over yourselves. With this sort of attitude you're so not getting tipped.)
4) restrooms (I like big mirrors, good lighting, that kinda thing;)
5) price (this one is a bit tricky, because if all the other points are attended to, the price ain't gonna be too low. But I still believe in reasonable pricing.)
Thus, places I like to go to for lunch: pizzerie Matylda near the hospital where I work, Jiny Stav, U Regenta, Kulovy Blesk. Okay, so it's all near where I work, cause like duhh, where else am I supposed to eat my lunches. Next time tips from all over Prague, promise.