I would take the approach suggested by Vickster, all bikes give you a different experience when ridden, you need to try some.
A good LBS can not be under valued with regards to getting you a bike you can be happy with and someone you can turn to.
Mail order bikes are great, but you need to do your research, if you need to send the bike back under warranty who is responsible for paying the shipping costs? - What would be your next step if you had an issue which was not resolved in a satisfactory manner, or the online/mail order retailer ignored your communication.... not everyone has a great mail order experience.
Find a great LBS who will give you time, support and let you try a few bikes... buy the one which makes you smile the most