gobiggergoredder

I agree with Enhance and would add buying from a reputable bike shop that will help you choose a bike that fits you.  Bike shoes that allow you to clip into the pedals is a must along with a good helmet and padded bike shorts. A really good seat to protect your ‘package’ is also very important. 

Make sure you get a nice lock...lots of bullies will try and take your ride when you go to the arcade...and be sure to lock it up at Blockbuster too...you might think you are just going to be inside for a second grabbing a game to rent...but that is all it takes for Blain McRoberts to mess with your bike.

I've been riding a mountain bike my brother got as a Christmas gift when he was 10 in the 1980s for the past 8 years, and it works just fine. And I've never used it as a mountain bike, I use it to ride on the streets/trails in Lincoln & Omaha.

Long story short I don't think you need to buy a nice bike before you decide if you're gonna stick with it.

That said, it's possible my bike is nicer because it was made in the 80s? Maybe a cheap bike now would suck. I'm not sure.

As ladyhawke said, get a good seat.