As for the guys that I work with, I'd have to agree with dabshire's nod to Nordstrand. However, I'd say that the best deal would be the relatively straightforward, no-frills NJ model. Once you start getting fancy, the "value" factor is somewhat diminished by the fact that you're spending money on cosmetics...the tone, build quality, and playability essentially stay the same. Another guy that I've been very impressed with is Mark Eshenbaugh. Again, an Eshenbaugh J Series is the best deal in my opinion. The "bang for the buck" diminishes when you start adding options, exotic figured woods, laminates, wood pickup covers, upgraded electronics packages, etc.
Otherwise, I've always thought that Peavey basses were a great deal. I don't care for them personally, but they have a full line of well-build instruments made right here in the goold ole US of A. Yamaha has traditionally been a very good, and often overlooked, brand as well. I'd also throw Ibanez and Carvin into the mix, and the Fender MIM line is pretty much the standard for beginner jazz basses these days. I've yet to try one of the new KSD basses, but if you get a good one, they look like they could eat up some Skyline market share.
All-in-all, the best valued in the lower end of the market seem to be the larger companies that focus on making quality utilitarian instruments, and the best deals in the high-end market are from new guys who might not have a large advertising budget or might not have picked up a famous sponsor/high-profile user yet...and there are a fair number of builders out there who fit into this category.