Most of my threesomes have been with 2 guys or 2 other girls. When my friends have asked me to join them with their husband I didn't enjoy it as much because I was worried about jealousy cropping up and/or I didn't know the husband that well. With guys its best if they are bi-sexual, or at least not homophobic. I hate when really straight guys are afraid to touch their dicks together inside me.
I love 3sums! I especially like a FMF scene, but MFM can be fun too with the right guys. I've also done FFF and those are super cool as well. If I had to list them in order of preference, I"d probably go with FFF, then FMF and lastly MFM.
I've never had a threesome, and I don't know if I'd like it... I suppose I'm a pretty possessive person, and when I'm with a man I want all of his attention to be on me, haha.
It's sex, sometimes it's great and sometimes it's just good! Seriously, all depend on the people and their mood.