My main bass - a Mike Lull jazz - because it's light, fits me nicely, has the right neck width (40mm), and I can change the sound on the fly from the pre-amp
My other bass, a 2015 T-Bird, because it's light, plays very fast and looks soooo cool, despite the odd playing stance required (you'll know what I mean if you've played one - kinda 'angry gorilla having a dump' stance)
My rig - EBS HD360 through two 12inch Bergs - it''s fairly light, has a great neutral 'hifi' sound and the amp goes up to 11
I have the amp in a 3u rack case with a korg 'pitchblack' rack tuner which can be set to do a strobe light effect...which is also way cool!