What are the main uses and your budget
First, I think that the faster, lighter, more "fitness" or "urban road bike" generally styles are the best bets in new bikes for under $750. However, I gotta ask what kind of riding you used to do and just how upright you feel you need to ride, as well as how long your rides are and whether you plan to commute or go way off road in the next few years?
If you rode road bikes when you were younger, you may find the call of speed beckoning you and may be happiest with drop bars after you get used to riding more. Personally, that's where my incremental increase in bikiing led me last fall. But whether you go with a drop bar bike (look for bars that can be adjust to seat level, making the tops much like flat bars on a fitness bike and the hoods much like bar end extentions, but giving you drop for a head wind or just a fun sprint) or flat bars (make sure you *** bar ends on them), be sure to avoid getting a hybrid with suspension unless you want ride very rough trails.
Some bikes I'd suggest looking at are the Trek FX, the Jamis Coda, the Giant FCR and the Specialized Cirrus. All much better hybrid choices for the mixed road and path rider than the heavy supensioned bike I bought a couple years ago. For entry level drop bar bikes Trek Pilot and Giant OCR offer more comfortable geometry than most. The Pilot especially can get the bars up to saddle height. Better yet, Cyclocross oriented all-purpose bikes like the Kona Jake or my girlfriend's Bianchi Volpe are what I'd call the ultimate "serious rider's hybrid". I mostly ride a Bianchi Axis now that I picked up used.