I have survived the trip to and from Chicago via the Megabus and I have to say that I would absolutely recommend taking this form of transportation. Both the bus and the clientele are decent and I felt totally safe. The bus really hauls ass; we got to Chicago in 4 hours with one stop to eat (there is a bathroom on the bus - take your hand sanitizer though). I had my own seats also (empty next to me) both to and from - excellent!
The actual bus is a double decker (which I think is WAY fun) with big seats that recline. My feet didn't even touch the floor so I would venture to say it is more comfortable and way roomier than a plane. The bus there did not have video screens, but the one back did and we watched Chicken Little and Night at the Museum. Take your headphones because you can plug in and drown out any cell phone talkers or kids.
The driver is also the luggage loader, announcer, and security on the bus. I handed her my suitcase and she responded with an enormous burp. "Whoo, chili..." was her response. I felt right at home :)
Ticket price to: $7.00, ticket price home: $28.00. Overall, great experience, totally worth it.