Hmm... that's a good question...
I'd say Greek, helped by the grilled eggplant served every now and then with the main dishes. I don't eat it very often, but I simply like the combination of the grilled meat with a variety of other grilled stuff, like the mentioned eggplant and other vegetables

.
*Forgot to mention the pita (mostly with gyros)*
Sushi is also quite high on the list, fortunately there's a good sushi-restaurant in Leiden which is also not so very expensive

(well, still have it max. once every 2 months or so).
Others... Italian too of course (where should one be without spaghetti

), typical German/Dutch food (the plain potatoes, meat and vegetables. And a Germknödel mit Mohn und Vanille Soße every once in a while is also quite likeable, though I have them with irregular intervals of several years (depending on going to Austria or so during winter

)
In winter my fav dish is mashed potatoes with sauerkraut (a few years ago we managed to eat that almost every wednesday, from mid october till december/january

)