I have to say that Dixieland is BY FAR my favorite ensemble. I don't know if it's the atmosphere of it being pretty easy going compared to any other ensemble or that I really can just have fun and play whatever (as long as I still provide the bass line) or that our instructor lets me sing sometimes. I can't do that in any other ensemble that I'm in. I find it to be an escape from my 8+ other ensembles that I'm "required" to be in (I'm not joking about that number either, last year I did 11 ensembles on top of my lesson requirments). Plus, not much beats the shout section of an up tempo New Orleans tune while marching down the hot/humid streets!!!
Now, I also voted for Tuba-Euph Ensemble/Quartet since our quartet this year was great and it looks like this next year will be even more fun. I didn't place it higher since it kills my chops since we played a lot of USCG Tuba-Euph Quartets that our professor arranged (Dr. Denis Winter) and the first tuba often plays higher than the first euph and I play a Sam Gnagey CC...not too fun to play high F's and Bb's above the staff for an hour on that horn...lol
I also voted for brass quintet since I love how when we "click" together, amazing things happen...however some of our past trumpet players (lead jazz guys) think that they can't practice more than once a week since their "chops hurt" as if mine don't hurt after playing 8-9 hours a day...

lol