I have no real regrets. I let DH talk me into to ultegra pedals, which I hated. Then I researched (thanks TE!) and switched to Speedplay Zero.

My only thing, I would have shopped more, but I love my LBS and picked what they carried. I am lusting after a Cervelo and if I had not loved my LBS so much, I would have shopped around more.

I never want to be off pavement so I chose a road bike. I had a MTB and never took it off road, so I sold it and never regretted it.

Determine what type of riding you want to do and your LBS can guide you in selecting the type of bike that works best for what you want.

I do need a second bike now since DS (4 yrs old) wants to ride to Philadelphia with me and I can't put a tag along on my carbon seat post. I will be buying a nice used bike for a tag along, although, it won't get as much use as my road bike.