Here's a tip for getting the survive 5 minutes on 6 stars achievement on GTA 4

I discovered this achievement when the game first came out, realizing it was such an easy way to get it, hoping no one found out about it. Now I'll let it out.

When you get the new Penthouse that Roman buys for you. Not the crappy ones, The one that has a flat screen TV and a laptop. It should be the one that you enter by walking in the marker through the elevator. Stand in front of the house and wreck havoc. One you have two or three stars, go into the hotel and take cover behind a wall. From there shoot any police/swat that walks in and chuck grenades through the door to wreck cars. Eventually you'll get six stars. Just turn around, walk through the marker to head upstairs, and wait 5 mins. The police cannot get you up there.