Best relationship: ENFP (duh, I suppose. Since I'm about to marry one)
Worst relationship: ISTP
I dislike even referring to what went on between me and the ISTP as a "relationship", but I'll stick with what works. The guy was a psychopath, and I got a nice serving of psychological -- and occasionally physical -- abuse from the whole ordeal. I stuck with it because I was in a phase of my life when I felt as though I didn't deserve any better. 0/10 would not recommend (psychopaths, that is. Not ISTPs in general)
To be completely fair, I had a bad relationship with an ENFP once as well. I can chalk most of the problems up to being too young at the time and in over my head, while he wasn't exactly headed in the best direction. My fiance actually Facebook stalked him last night out of curiosity (and also to stir me up. He likes doing that), and... let's just say that I'm very, very glad that someone talked me into dumping him six years ago. I don't even like to think of where I would be now if I had stayed in that relationship.
I'm so jelly. I never told you congrats about getting engaged by the way, congrats

I love me some ENFPs but your account is really tellling, in that any type (even your favourite) can be embodied by a person who isn't right for you. And you not right for them if you're too young to deal with both of your issues, grow together, understand each other etc.
I'm pretty sure that the man I was closest to was either an ENFP or ESFP, either way he was lovely, it just wasn't going to work - I wouldn't have been willing to compromise with his fickle nature and found him immature and I'm sure he would have eventually found me boring and unable to keep up with what kept him 'excited'.
Best: My husband! (unsold on type but going with xNTP, though he has only tested as INFJ)
Honorable mentions: INTJ and ENFP
Worst: ISTP (I really don't feel like going into this one)
Honorable mentions: ESTP and ENTJ
Again with the ISTP...I thought there'd be a pattern emerging here but I didn't think it would be so close to my own experience. I generally find INTJs make good friends to me because we generally want the same things in life and understand how life can be hard and rewarding both as an Ni dom, but I've never felt it appropriate to date one, which is similar to how I feel about Fi doms in my life.
Worst: humans (not sure of their types)
Best: cats (INTJs)
What? No durian? I'm disappointed. I think as our animal representative, we'd likely share cat with the INTJs or if not, we'd be a cuter, slightly more approachable type of cat, that acts more like a labrador. Or perahps we're owls? I could go for that
Best: INTJ (romance), INFJ (Female friends).
Worst: ISTP - Little nugget of psycho.
ENTJ - Way too controlling.
I'm always happy to see Ni doms getting together

And yes...looks like I was right, the ISTP pattern I was already wary of. At least I know I'm not alone in my view that said ISTPs in my life were psychotic. I thought I was going a little overboard labelling them that, but I guess not.
I have to admit I am a little shocked, and yet I feel a little less alone now. I just (a few weeks ago) had an awful, the very worst encounter in my life end, with an ISTP. I didn't think there was any type I was less compatible with than ESTJ 'on paper', but since I've never met an ESTJ that I could type for definite, ISTP now takes the cake. I'm also pretty sure that a similar, but thankfully shorter encounter back in my high school days was with an crazed ISTP too. But this one...wow...I'm never going back there again. I've never felt so humiliated, stepped-on, spoken down to and honestly, abused in my life. No one has ever made me feel so awful.
On a more positive note, despite hearing about the challenges, I'm really curous to meet an ENTJ!!! I don't think I ever have and I wonder how we'd work together. I can lead groups perfectly fine on my own but my ego doesn't take a blow to allow someone else to take the lead, as I've been told ENTJs want to lead. The 'too controlling' stereotype worries me however.