After buying myself headphones from bose I thought it would be good to also replace the crappy integrated audio with something better. After some goofing around I bought Sound Blaster X-Fi Surround 5.1 Pro:
The good thing is that it, surprisingly, works even in the 5.1 surround setup out of box (on F-15). The not so good thing is that unless you plug it in during boot you won't get anything more than stereo. I wonder why :-D The sound is pretty good, I haven't made any measurements but I noticed a significant improvement both on the sound and noise front (basically, the music sounds better and noise is beyond my recognition level). So basically I'm happy with this buy. Of course, pulseaudio makes life really easy in this case, I wonder how it would have worked without it (alsamixer just crashes when trying to change device, xfce4-mixer does not see the card directly, only via pulseaudio).
However, this also came with a simple remote control and I have no idea how to make it work… Pointers to how-to's for dummies appreciated. Not that I care that much, but would be nice to have it also working as opposed to just collecting dust ;-) Same goes for the metallic volume knob (apparently it could be also handled via lirc).