This thread should be renamed - into "name your city"
Personally, I liked Ljubljana a LOT. This city, which is 5 times smaller than nearby Vienna, impressed me a lot more than Vienna, with its livelyness, architecture, the restaurants that line the Ljubljanica river (for a moment there, it seemed Ljubljana had more restaurants in its downtown core than much larger Belgrade)
And the language spoken there of course, doesn't differ much from Serbian so you don't need to strain yourself too much
Its definately the #1 city on my list of places that i'd like to re-visit. Probably will this summer