First approach: I had no health insurance at all. Most people will tell you this is a bad idea, and it probably is. I got a check up right before I quit my job. This was the first time I had been to a doctor since I was a little kid, so I wasn't too worried at the time.
Second: I finally decided to get an HSA (Health Savings Account). This covers you in case of a disaster. It's a high deductible plan where you save money to pay for health expenses. For a non-smoker in 20's, the cost was roughly $60 a month, and you could sock away a few thousand a year (forget the exact number) for health expenses. I think the exact maximum has changed somewhat. You aren't taxed on that money for the year, and if nothing happens, you just get to withdraw it when you are in your 60's. I thought it was a pretty good deal in that I was willing to cover smaller medical bills out of pocket, rarely go to the doctor, and it seems to have the benefits of a retirement account (like a Roth IRA + Traditional IRA).
Third: Last year I got married. This is ideal in that I'm fully covered at a low price and no longer have to worry about it.
There are many threads on this very topic - do a few searches on searchyc.com because this comes up a lot.
I had one friend that tried one and had major issues when they were forced to go on a long term medication.
2. Learn your local state laws. In WA it is illegal for an insurance company to reject treatment due to pre-existing conditions if you had maintained continuous coverage. Hence it is very important not to have any gaps in your coverage!