What bike should I buy?

I hear the red ones are pretty fast!

Doesn't matter, even the light red (pink) ones are fast, if you wish to get in touch with your feminine side.

Ryan had a good idea, though, especially if you're just starting and find red bikes a little intimidating. A little black spray paint has been known to slow things down significantly. Then, as your skills progress, a little paint remover will restore the red bike speed.

Got to disagree here, buy something within your budget. I started on a $650 entry-level Specialized Allez with mostly Sora components, put over 10,000 trouble-free miles on that bike before I upgraded. Even then it was more for the frame upgrade than the components.

If I felt I had to spend $1000+ for a 105-level bike, I may have never started cycling.

It all depends on your budget. I think you should plan on at least $600 + accessories though. Below that and you have a hard time finding a quality bike.  From there you can go up to $3000+.   Decide what you will be using the bike for (as in only Triathlon or all kinds of road riding) and then go see what you can afford. The local bike shop should be able to answer all your questions and recommend bikes that fit you and fit in with your riding needs and budget.

You have outlasted me in a game of wits.  Beautiful comeback Bear!  Laughed out loud at work, now coworkers are wondering why my job is so funny.

You should buy a bike that you will ride a lot.

It should fit you reasonably well. It should be within your budget (maybe a little stretch). You should like the cosmetics (color etc). The more you like your bike, the more likely you are to ride it a lot.

Beyond that, what matters is the riding, everything else is full of sound and fury signifing nothing.

Chances are the $1500 bike will be no faster than the $300 bike, given that each is powered by the same engine.

What you get with the more expensive bikes is (theoretically) a better designed and constructed frame, possible made of better materials, more expensive alloys, etc., and better components that add durability, accuracy and precision.

As you add to the cost of the bike, you get increasingly fewer marginal benefits (principle of diminishing returns). It's really up to you to determine the equlibrium point at which an additional dollar spent gives you a marginal benefit that is worth less than a dollar.

I somewhat second this opinion.  I have started out with a $600 trek 1500.  Have ridden it for a year so far with no problems.  Almost 800 miles or so on it.  ( I KNOW BEAR MORE T.I.T.S)     But beside the fact components aren't the most important thing.  Fit is.  If your on an improperly fitted bike and try to ride 20-50 miles you will feel it fairly quickly, if you have a poor fit