I'm also a fan of Cialis mostly for its long lasting effect. There's been more than one occasion where i popped a Viagra in anticipation of a romp in the hay with the wifey only to have ended up having an argument and wasting a perfectly good Viagra.
On a side note though, since i have a bit of a sinus problem already I'm looking into PT-141 as an alternative. Haven't tried it yet, just doing some reading..