Viagra is the absolute best for me. Don´t have any problems getting it up or holding it up except for when I have been drinking tons of alcohol... Viagra gives me the boner from hell. Even totally intoxicated I can bang for hours on this shit. Cialis also works fine, but doesn´t give the same rock hard erection you can break bricks with.
Another problem with Cialis is actually that it lasts for 36 hours. I had this massive erection at the hairdresser (was a pretty cute girl at Tony&Guy, but still...) and my friend reported that he got a boner when taking a dump... he actually had to wrap it in toilet paper because he didn´t want it to poke the inside of the toilet
Buying the authentic stuff in HK was no problem. I just went in to a random Pharmacy with a guy behind the counter and asked if he had Viagra. He wend down in the cellar and came up with the real thing. Cost me 360 HK$ for a 4-pack of 100s. A tip to you all (either it is Cialis or Viagra) - buy the big ones and divide them in 2. A pack of big ones are only a little more expensive than the pack of small ones.
Oh, by the way. I tried taking a 50mg Viagra and a 20mg Cialis in one go - that really hurt. My boner just didn´t want to go down again for hours after I was done fucking. I was wasted and figured I needed a proper boost, but man was I in trouple (not to mention the damage on the chick).
50mg og Viagra is higly recommended - just remember to take it at least 30 min. before the action kicks in