Guardians... hands down.
Personally, I Love regular tally's as they are second favourite cards next only to the Guardians. If you're hoping to pick up the vipers hoping that they're basically black Tallys, then you'll be let down. In my opinoin, the Vipers are the worst cards I've ever held in my life. They feel a lot like the Masters, which is alright if you like the masters... but the black ink just kept rubbing off on my hands after a day.
The gauardians, on the other hand, have been nothing but amazing to me... the design is kind of extravagant for me, but they feel really good so I use them.