I'm sure we've had some threads on it here; I know it's been discussed at length on other forums I belong to.
I use a dedicated belt from
http://www.thebeltman.net - and am about to buy another from him. I could never get a good fit even from the thick department store belt I originally used. I love this belt - my holster does not shift at all when wearing it. (I use either a Milt Sparks VMII IWB or a Serpa OWB)
A good gunbelt will be constructed of two layers of leather with the grain alternating. This creates good stiffness and prevents stretching. I believe the stiffness is more important.
A friend at work finally ordered a good gunbelt after having his CCW for a while. It came in a few weeks ago and he told me" I did'nt believe it would make such a difference - it's amazing how much better this is. I'm glad I listened to you".
I consider the belt to be the thing that holds your entire defense system together. You're carrying a sidearm that cost you anywhere from several hundred to over a thousand dollars, a holster that may have cost over a hundred, premium ammo... and hanging it all on a seven dollar belt from Wally World? I too was hesitant to spent close to ninety dollars on a belt - but it has enhanced my carry experience immeasurably. Eat at home a few nights this month and spend the money on a good belt instead - you'll thank yourself.
+1 on The Belt Man belts. Have one and wear it daily. Love it.