I have gone to three of the past five in Indianapolis. My dad has a friend who buys (or is give to) around 25 tickets each year, and he usually gives my dad two. If my dad needs more all he has to do is ask.
Each time we go we sit in the Paddock by the start finish line and right across from the pits. Its a nice place to sit (shade), but this year if possible I would like to sit at one of the corners.
Sometimes though, I would just rather watch on tv. We have to leave real early on Sunday to make it from Chicago in time, and after the actual start of the race most of us are watching on the monitors anyways.
I'd defiantly recommend it to anyone who had the opportunity to attend.