The Gemeinhardt tubas- small Bb, Eb, F, and big C. The F was ok, but that Eb really shone. I still don't like dependent 5th valves, and would much, much prefer a setup like a 2341.
The Adams/Hirsbrunner tubas. The F was quite nice and thankfully nothing like that terrible piston Hirsbrunner Eb I played at the SOM-
Miraphone contrabass tubas. The 1291, 1291 Bb, and 291 are all nice horns, but my favorite is still the 191. A little wonky for me on C and B below the staff but a wonderful sound and a fantastic low F.
Small and big Willson Eb's, big piston F, big piston Bb (but aren't they all big?

). That little Eb is a
fantastic horn- easy to play, solid low register, nice sound, awesome retro "feel". Willson reps told me there's only a few of them in existence and that there will be a 3rd F in a similar format.
This is my pick of the litter (roughly tied with the small Willson Eb and MW 2250), the Miraphone 1281 F. Sweet, sweet horn. Great sound, awesome low register, good intonation, so easy to play,... Markus Theinart was nice enough to take this picture for me.
The wonderful, as always King 2280 and 2341. Nice full sounds, good intonation, bangin low register on the euph,... I also played the 2341 copy. It wasn't quite as good as the King. See the pBones? They play ok, but oddly enough everyone outside of high school who picks one up plays
scalding jazz licks on it.
The excellent MW 2250's. Big, clear, colorful sound, solid low range (only slightly edged by the 1281), fun to play,... I do think they look a little odd though.
Lousy picture of the big Besson top valve comp Bb. Very easy playing horn with a pretty solid low register.
Partial view of the Courtis dual Hagmann bass trombone. Heavy as 20 sousas, but still a monster horn.
The Miraphone bass tubas, right to left- 1281 (see above), 281 (very nice horn, easy playing, solid sound), 181 (kinda odd to hold but still a player), and the big Star (nice horn, deeper sound than all the F's but possibly not quite as easy to play?).
I thought I also had a picture of that giant Jupiter contrabass flute. Oh well. The Edwards and Getzen bass trombones rocked as they tend to do; I didn't care so much for the stock indy Bachs, either the rotary or Hagmann.