I got a MIM Fender J/P hybrid off of Ebay for less than 300 bucks and I absolutely love it. It's comfortable, reliable and attractive. I bought an SR505 as a backup, mostly on the strength of its tighter string spacing and the Bartolini pickups and preamp. But since I brought the Ibanez home, it's quickly become my primary bass. The construction is very solid and the tones are very flexible.
I think the big thing with these basses is that there's no one answer that's going to work for everyone. The things I like about a bass may be the very same things that another player hates about it. Even if you buy online, you should try to play the basses you're considering by checking them out in a store.