Prison overhauls. Which are not so buggy as the one on LL.
Why? Because it's fairly easy to get bounty in Skyrim, especially with mods, but once in prison there's nothing to do except, clicking once and by that finishing your time. Click, loading screen, you're out. I mean REALLY? That's all?
There should be tasks to do each day of the sentence, guard abuse, corrupt guards, friendly/unfriendly prisoners, skooma trade, you know, the whole suite.
Daily activity ideas:
1) "Chop ice" The Chill (Glacier ice - not from the sea) to supply the town with enough fresh water - Currently there is no fountain or river in Winterhold, people probably to melt snow or something.
2) "Work in an excavation". Saarthal extended.
Evening Events / Miniquests
Bonus for making it SL compatible.