Trek all the way. Get something that will be desirable to resell in case you dont get into it. Minimally I would get a Trek 1.5. Check it out -->
http://www.trekbikes.com/us/en/bikes..._1_series/1_5#
This is what I bought and even though I dont have much time to ride anymore its an unbelievable bike and I want to get out just because its so pretty.
Good luck. You'll love biking!!