Great thread. The Q to myself is rather, Why can I not sell the basses I own? lemme see...
JayDee Supernatural Series3 - 1987 - Because it sounds and looks unique - quirky maybe, but it's part of the charm. Because it feels great with .30. Because I've got for the longest time. pix here:
http://bassaxe.blogspot.com/2010/01/jay-dee-supernatural.html
Wal Mk1 fretless '89. Because it's one hell of a f/less. And because it cost me a '73 Fender Precision.
pix:
http://bassaxe.blogspot.com/2010/01/review-his-majesty-wal.html
Wal Mk3 5er. It's one of the best 5er I have ever played, and I've played a helluvalot of them. Because I love the understated Wal class and unique sound. no pix yet, sorry.
THE Steinberger. '82. This bass can rock, funk and everything in between. It plays like many basses would just dream to. It's a plug n play wonder. Its design is a love or hate thing - which is what I like about it

. It's like a van Gogh, there're only a few out there. If you own one you hold on to it.
pix:
http://bassaxe.blogspot.com/2010/06/steinberger.html
Tobias Killer 5, '92. I don't play it that much - blame in on the Wal - and it should probably go. But it's so beautifully built that I just can't let it go.
pix:
http://bassaxe.blogspot.com/2010/01/tobias-bass-killer-b-pre-gibson-5.html
The Über-Jay. Well, I built this one and it's the first prototype. It's got all I want in a bass and I love it. The next Ü-J will have to go though - and I better get used to it

pix:
http://www.talkbass.com/forum/showthread.php?t=620583&page=12
Since the Ü-J, I'm not craving for other basses. I'm fully focused on improving on my design. But I don't rule out new entries