I'd pick Blood up in a heartbeat. The "I live .... again" plus the sound of your coffin lid sliding at the start, the cackling maniacal monks all over the place, throwing dynamite at zombies, lots of secrets to discover, including "super secrets", great weapons, gory but not too gory, cool game from A to Z. Add Plasma Pak and Cryptic Passage to the mix and it's even worth $9.99 for me.
I never tried Shadow Warrior but I hear it's OK and I've kind of ... got a thing for old-school FPS games, so I'd probably buy that at some point as well.
Bring them on!
I was hoping I wasn't the only one waiting for Blood to be released. :)