Like others, my first 'adult' bike, bought around 12 years ago, was a Walmart bike. Wanted something that wasn't too expensive as I wasn't sure at that time whether I would like cycling enough to invest serious $$ in a bike.

Turns out I did like cycling that much...rode that bike for two years sold it, bought a used hybrid from my favourite lbs, sold that bike and bought my road bike.....then my commuter/mtb.....latest addition was a lovely turquose beach bike (and I can hardly wait for the weather to warm up so I can ride it)!!!

As I recall, that used hybrid actually cost me less than the new Walmart bike, so + 1 on the recommendations to look for a used bike if you decide you like cycling that much - and I bet you will, its addictive - lbs, craigslist - folks from my cyclling club often are selling or know someone who is selling.