I pirate/emulate the retro stuff, games that usually aren't sold anywhere where I can get them. (I don't do ebay)
That said, I do fully intend to play pokemon and Golden Sun without a DS. It's not a money issue, I just REALLY dislike the handheld itself so I won't be buying it. Since I do want to play those 2 games, I'll use an emulator.
That is mostly the extent of my piracy, NES games, Snes games(I will be buying an actual snes in januari though), Neo Geo, and super smash bros on N64.
Logically: "I want to try it but there's no demo" is NOT a justification. Not at all. The only way to really justify piracy is to adopt an individual (nihilistic) paradigm and forego the standard socio-moral paradigm, as it eliminates the need for justification entirely.
As long as there's enough good guys, I'll be one of the bad ones.