For some, it depends on how last-minute you're talking. DRS and Bee have lottos that take place 2 hours before the performance and 1 and 1/2 hour before the show, be there before then.
Some of these shows have rush, I know the Producers does, you can see if they have those tickets available.
If nothing else, you can always go to the TKTS booth. If nothing else, I'm almost postivie Rent would be on there for half the price. Good luck!
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli