I'm betting on Ripple
I'm betting on both! They are two completely different systems with different use-cases. The cryptocurrency pie is incredibly large and Ripple does not detract from Bitcoin nor vice versa. In fact, Ripple makes the pie larger!
Even though I can't stand the alt-coins, it is interesting that Ripple will also benefit the alt-coins since it will make them more liquid. You'll be able to spend your litecoins at any merchant that currently accepts bitcoin, when bitcoin "bridges" appear on the Ripple network.
What I keep saying, which unfortunately gets drowned out in the chorus of "scam, bla bla" is that Bitcoin users already have to extend trust! Except for the very few who don't use an exchange... See:
and what i keep saying and you keep ignoring is that if mtgox was shut down tomorrow Bitcoin would still function just fine b/c of other exchanges, localbitcoins, and p2p. the POW will continue to incentivize miners to secure the network while at the same time not being a centralized point of weakness.
Ripple, otoh, will depend on centralized gateways (banks and other financial institutions) that, if you're lucky, will play ball with Ripple and submit to Opencoin instead of their chief benefactor the Fed. and when they decide to change their minds, Ripple will be hosed.
in Ripple, there is no incentive for individuals to validate, unlike in Bitcoin they get paid as miners. this is a significant difference.