Let me begin.
Gashmiyus: I prefer freshly fried latkes any time (although fresh donuts do come in a very close second). Once I've had a donut I'm done whereas with latkes I can go thru a whole plate of them!
With donuts, kids usually eat the jelly and leave most of the rest of the donut so in future we might aswell just put a jar of jelly on the table instead of buying expensive donuts.
Ruchniyus: There are halachic issues with donuts. In Yoreh Deah 329 is the big machlokes whether or not to take challa from dough intended for frying or cooking. Then is the debate in O.C. 168 whether they are pas haboh b'kisnin or not, so the mishna berura advises that a yarei shamayim should not eat a shiur seuda of donuts outside of a bread meal.
So I think all things considered, latkes win hands down.