I'm not particularly a collector of basses, unlike some Canadian guys, but I do have a few instruments that I love to play. These days, I'm mostly a Fender guy, leaning on the classic Jazz bass for rock and the Precision funk machine for funk, R&B, etc. I have a couple of Warwick Thumbs, along with an absolutely beautiful custom built MTD 535, but I don't play them too much these days. I also have an Englehardt upright which mocks me from the corner every single day (and I played string bass in the DC Youth Orchestra as a kid).
I use a Genz-Benz Shuttle 6.0-12T which I love but which is also unfortunately discontinued. This is a fantastic pair to the Fenders, especially the P bass.
I also use a Mesa Engineering Subway D-800+ head paired with 2x10 diagonal cabinet. It's a killer combination, with great mid-range control and tone, but it isn't quite as lightweight and portable as the Genz-Benz. It certainly has tons of oomph though!
I'm a huge fan of the Hipshot Bass Xtender. I have them on all my 4-strings (except at the moment, the recently Jaco signature Jazz). It's one of my favorite toys. The Hipshot is a special tuning peg with a lever system that lets you tune a string down a few notes at the flip of a switch. Normally, you set this up on a four string bass so that you can quickly tune the E string down to an open D, although you can actually go even lower.
To use it, you just reach up with your left hand, and flick the lever with your thumb in a very fluid motion. The low note (i.e. "open" position) is tunable, so you're not stuck with just the D, but the open D tends to be most useful for the songs I play. It's almost as easy to flick back up to E, and the Hipshot stays in tune very well in both the D and E configuration.
I played a few songs on the last couple of Cravin' Dogs records where I had to actually flick the Hipshot in the middle of the chorus, because I needed to get to an Eb. I had to figure out where the chorus bass line played an A, then I used the open A to free my left hand to trigger the Hipshot. Then a little later, I play another open A and can flick it back up to normal tuning. It takes a little dexterity, but it's pretty seamless!
I also have Hipshots on both my E and B string on my MTD 535. This lets me get down to a low open A, and while I haven't used that, I have recorded songs where I wanted a low Bb, and the Hipshot gives me that.