Depends on who I'm with and what it's for, but I'm usually around 10-15 minutes early. If it's for a party or big social event where my presence isn't direly important, I usually go 30 minutes-1 hour after it starts. The latest being 2 hours.

Some of my friends are always late (Asian time lol) for plans though, so I gave up and started going to things 5-15 minutes later than planned and STILL be on time for them.