The problem with asking on a forum like this what will work best is that you are going to get answers that work best for the posters. That may or may not work for you! Here is what you need to do...
1 Spend $75-$150 and get fitted by someone (preferably by someone not selling you a bike. Your comfort is determined by your contact points on the bike (not the geometry).
2 Decide what you want to the bike to do and make a list. Do you want fenders, a rear rack (frame mounted or seatpost mounted), handlebar bag, panniers etc. The amount of gear and weight that you will be carrying should determine the geometry of the bike. Bikes designed to carry bags etc will generally have more relaxed geometry. If you want to go lighter then a bike with tighter geometry might be the ticket. Do you want STI (brifters), DT(down tube) or bar-end shifters? What level of components do you want (ie 105, ultegra, DA for Shimano).
3. Take your list of requirements and then go shopping! You will find that will narrow your lists of bikes down to where you can choose the one that is going to be the best bike for you.
There are lots of things to look at but you will be much better off sitting down and making a wish list. You will still probably have questions but it's easier to take them bite by bite instead of a whole chunk.