I read through a bunch of these comments before commenting (I like to see what people say about mods!). I own 3 basses, A Squier P-bass which is the first bass I ever owned and have modded significantly, another Squier P-Bass that I got for a steal on craigslist that was supposed to be my secondary bass (I never got around to using it much) and a Fender Kingman Acoustic bass. The Kingman I am obviously leaving alone. When I bought my first bass, I knew nothing about tone and sound other than I knew what sound I liked. As the years went on and I became a better bassist, I studied the ins and outs of the instrument, from different pick-ups to what strings I want to use and what amp I wanted. I became obsessed with finding my perfect tone. I ended up getting the amp I wanted, messed around with different size strings, and found the pick-ups I wanted. My Squier P-Bass off the shelf was black with a 1-ply white pickguard and a rosewood neck. I ended up getting SPB-3 pickups, and found a custom tone so I only have a volume knob. I added a 3-ply black pickguard and scratched out where it said "Squier" on the headstock and wrote "Nick" (my name) in cursive in its place. I eventually added strap locks and a white Ernie Ball strap with a couple of black accents added here and there. A couple of other small cosmetic things here and there, and there is my bass. I haven't done anything else to it in years (partially because I had to take a break from playing it for a few years) and while my knowledge of the instrument is not what it once was, I still love it and am now starting to continue my journey to find my perfect sound. Every time I think I have found it, I listen to a song and hear an even crisper tone and I immediately want to chase it.
To me, the #1 thing I look for is tone. To me it is what separates you from the next bassist. Two people can have the exact same instrument but can sound different. After that, playability, reliability, and even looks are all important too. I didn't exactly take care of my bass in my playing heyday because I played a lot of punk and metal music and it shows, especially with the cheaper Squier wood. I have been a lot more cautious with it to preserve it because I would like to keep my first bass for the rest of my life. My bedroom is pretty small so in order to save some space and not feel cramped I would always put my bass away after playing it. Recently though, I don't even care about that and I leave it out on display on a stand. I do it because every time I look at it I get an urge to pick it up and play it. Even if the sound gets dull I'll slap on some new strings and the excitement is right back there. It's like a woman (or man) that you love, after all these years you still look at it the same way, it's something special.
My journey for the perfect tone has had me looking at other instruments recently. I've always loved the P-Bass and the way it sounds, but a month or so ago I really got into the J-Bass tone. Then I started digging basses that had a combination of P-Bass and J-Bass pick-ups. I have plenty of time to look around and decide which route I will end up taking. Maybe way down the line I will drop some $$$ on the customs shop! That's the great thing about music - even if you're not a rockstar you can carry it with you the rest of your life.