Xbox 360 piracy is too risky. Even if you don't care about online at all, if your 360 breaks down within the warranty period, you are SOL and have to buy a $200 Arcade replacement. Some would argue that it's more worth it to risk that happening because you could make up that $200 + modding costs and DL DVD media costs by pirating four $60 games. But still, I think that's pretty risky. In the end, it's up to you whether you think playing $1 360 games (price of DL DVD media when bought in bulk) is worth the risk and giving up online. Probability-wise, you do get more bang for your buck with piracy if you don't care about online (yes a 360 will generally last you more than 4 games worth! lol). But still, it's iffy. If money was really a big problem, I could just simply live off $20/month gaming-wise (that's what my 2 games out unlimited rentals subscription costs) and stop buying games. There isn't a downright clear upside to 360 piracy like there is with say PC or PS2 piracy.
At least with PS2 piracy, there's pretty much zero risk to using a soft-mod method since you don't even have to open up the console to get those to work. Same with DS piracy (Though if you don't know what you are doing, you could end up bricking the DS). So that's why I've no worries about pirating games from those platforms. And the PC naturally since you don't have to mod hardware for that obviously seeing how it's an open platform.