There are two version of the SBLive! Value, the first one is it's own distinct card...analog only.
The 2nd revision is the same PCB as the X-Gamer/MP3+/Platinum (non-5.1 versions). It has the exact same capabilities as the X-Gamer, but no software bundle.
As for the card, personally I'd get:
Turtle Beach Santa Cruz
Hercules Fortissimo 2
Hercules Game Theatre XP
All 3 use the same chipset...
The TB has front/rear analog and a versa jack that can do 1 of 3 things (set in software):
[*]SPDIF output (you need a mini-stereo to RCA converter)
[*]Center/Sub analog output
[*]Dedicated headphone jack
The Fortissimo 2 is pretty damn cool looking (not sure if it's avaiable just yet though)
4 analog outputs: Front, Rear, Center/Sub, and a dedicated Headphone jack (don't need to swap cables between center/sub and Headphone like you do with the cruz).
It also has optical I/O ports on the card

(No brackets required, the 4 analgs are on a minijack-4x ministereo cable, sorta like the A.Edge).
I've never seen any reviews but I assume it will have the same clean analog output of it's big brother the Game Theatre XP (which is based on the same chipset)
The Game Theatre XP is like an SBLive! Platinum on stereoids
It's got a breakout box that sits on your desk rather than ina drive bay.
It's got USB ports, GamePort, audio I/O (digital and analog) and a headphone jack. It's pretty damn sweet if you want the break out.
The problem I have with the AE is that is applies QMSS to Stereo sources always, no way to turn it off. So Mp3s will get expanded to 4 or 5.1 speakers....and while I don't know exactly how it does it, I'm not a big fan of processed music.
(I've never actually heard it, the guy I know has the AE has 2.1 speakers)
Personally I plan to get a TB Santa Cruz. I know it has nice clean analog outputs, and I can use it with a nice 4.1 speaker set and headphones at the same time.
I don't really need digital I/O on my soundcard so I'll pass on the Fortissmo2 and I don't want the breakout box.
Edit: Oh yeah I don't give a crap about 5.1 speaker sets, 4.0 is good enough for me (don't have a place or a desire for a center and all the good 4+sub sets just take 4 inputs and filter the bass themselves which I prefer for alot of reasons...that's a whole new thread though), so I'll use the Versajack in headphone mode, as I don't want Center/Sub or Digital out. If you want 2 or 3 of the Versa jack functions I'd go with the Fortissimo2 so you don't have to swap cables.