THE ANSWER IS:
A = Lakland
B = Squier
C = L-2000
D = Sterling
E = Bongo
I must admit, after listening to the Bongo clips, I agree that the strings do sound a little dead and the Bongo does sound brighter than that clip would lead one to believe. Mea culpa.
On the other hand, a couple people nailed the identification dead on and I am quite impressed with CheckEverything & Lord of Paaren.
Indeed, there were three "jazzes" as GeneralElectric pointed out and some people had a hard time distinguishing between a US-made L2000, a more upscale Skyline, and a Squier with new pickups. I'm not gonna comment. Come to your own conclusion. Of course this only refers to recorded tone. Playability is a totally different can of worms.
Thanks for "playing". If any of you want to hear any of those basses dialed in differently, or even the Bongo with a fresh set of strings (give me a little bit of time), please ask. If these types of clips can help you make a decision if you're considering getting any of these basses, I'd be glad to lay some more tracks.
Cheers!