I actually dropped out of university because of work. I started making $35k/year plus freelancing (usually another $10-20k) when I was 18, and while I tried to keep going to school for awhile during work, it was too hectic and I wasn't interested in class anyway/anymore. I was already working in my field of study and felt I learned more on my own.

Sometimes I'm bummed out I never took some lower-level, nitty-gritty CS classes, but I don't miss university in general, and I've learned a lot of the theory/low-level stuff you don't just "pick up" through teaching myself and learning from other programmers at work.

Four years later it seems like the right choice, as I'm making a lot more than I did at 18 as a full-time, salaried employee at a small startup-ish company.