a) Answers without reasons are more or less alma mater shoutouts, I recommend you ignore them.
b) Stanford and UIUC tend to be more entrepreneurial than other CS colleges (I find Carnegie Mellon/MIT tend to lean towards academia), but I'd say it's more important to go where you'll be happy...visit everywhere and find a place that won't drive you insane, since nothing kills the startup spirit faster than being forced to work day-in and day-out on things you don't enjoy.
b) Stanford and UIUC tend to be more entrepreneurial than other CS colleges (I find Carnegie Mellon/MIT tend to lean towards academia), but I'd say it's more important to go where you'll be happy...visit everywhere and find a place that won't drive you insane, since nothing kills the startup spirit faster than being forced to work day-in and day-out on things you don't enjoy.
That being said, I love Carnegie Mellon :-P