Hi cap under $600, you could spend a week looking at pistols that meet that criteria, there are a bunch of em. Glocks, not a big fan, but I have one, Beretta, love mine, very accurate and reliable, CZ, Taurus 24/7, I have 2, both are accurate and also 100% reliable, XD & XDM I have one of each, both are solid pieces, very accurate, 100% reliable, S&W's, ect, ect, holly cow, the list goes on and on.
Your best option would be to either rent some, or go out and handle a bunch of them, then buy the one that scratches your itch, or maybe buy 2 used one's that keep you close to the $600 budget.
The nice thing about AL's, is that even the decent one's aren't terribly expensive, and there are a lot of them to choose from.
If it were me with that budget, my first choice would be the XDM. I just put about 500 rounds of my full tilt JHP Longshot reloads through mine last weekend. I had trouble putting it down, it just shoots so comfortably and accurately in my old small hands. It feels very refined, that same feeling you get when shooting a super clean S&W revolver.
GS