Savage.
I started with a xxx-nt, got a t-maxx 2.5, upgraded it to a xtm conversion 21 tmaxx, traded the xxx-nt for another t-maxx 2.5, converted it to a 2wd maxx, got a savage, parted out and sold both maxx's, bought the NMT recently for something small but still 4wd.
The xxx-nt was nice for what it was, but for where I have to drive, 2wd and low ground clearance was sucky, which is why I got the maxx.
The 2.5 on my maxx sucked since day one. Followed the dvd to the letter, but never saw it pull a wheelie. Tune it one way, temps would hit 340 and flame out, richen it 1/8 turn and it would flood and die... tried upgrading the head, didn't help, tried installing an OS carb, didn't help much. Tried installing a OS 15, to underpowered... that's when I converted to a 21. Then I had to replace the whole driveline, but then diffs and bulkheads were still an ongoing problem even after buying aluminum. Just a bad design to try and shove a 21 in...
Got the other maxx, converted it to 2wd and installed the OS 15 in it. Liked it quite a bit, but still had the bulkhead and diffs issue. That's when I bought a savage roller.
I installed the engine off my 21 maxx onto it and pretty much never drove either maxx again. Parted out the 2 maxx's and got about $600 out of them ($1200 roughly into both of them). I drove the savage all summer and beat the living crap out of it after upgrading the shocks. Added some odds and ends to it just to make it more durable (cvd's, roll cage, OFNA/dubro linkage, lunsford turnbuckles, MP servo saver).
Then I decided I'd like having something smaller again just for tinkering around with and I got the HPI Nitro MT (the predecessor to the MT2 I think). I've since done some mods to it, upgraded the shocks, made a steel plate to support the center spur and engine to reduce flex, put UE Shocks on it, put RPM rims/losi tires on it and installed an OS 18 cv-r(x). I haven't run it much since the new tires and engine. It got too cold, but the few times I did have it out, it freaking flys.