Having married a chasidishe boy and not coming from a chassidishe background, the technical differences are:
1) Tisch – Friday night after the meal the men go to the rebbe
2) We follow one direction, we have one dayan, specific minhagim, there is no wishy washy…
3) My husband goes to the mikvah every morning (what does that mean to me? lost towels!;) )
4) Levush
5) speaks to our children in Yiddish
6) My husband doesnt have conversations with females other than family. He will not strike up a conversation with my friend or neighbor.
In other aspects, the fact that my husband is very warm, sings loads of zmiros etc. I dont know if this is bec he is chassidish, I am sure there are vareme litvaks too.