It depends on what features you want. Beretta 92 variants currently being made, in order from least expensive to most expensive:
• M9 - Standard sidearm of the US Military since 1985, dot-on-post sights (fixed front), all M9s are made in the USA.
• 92FS - Differences from the M9: 3-dot sights (fixed front), radiused backstrap (a very slight cut out at the top of the backstrap to allow a slightly shorter trigger reach), slanted dust cover versus the straight dust cover of the M9, 92FS models can either be made in the USA or Italy.
• 92G - Same as the 92FS in every way except the decocker lever automatically springs back up into the fire position after it decocks the hammer - there is no safety.
• M9A1 - Has the sights and radiused backstrap of the 92FS, but has checkering on the frontstrap and backstrap instead of grooves, a beveled magazine well, and a 1913 rail on the frame. Made in the USA.
• M9A1 Compact - Same as the M9A1 but has a shorter frame, slide and barrel, and comes with 13-round magazines, but will accept all Beretta 92 magazines. Made in the USA.
• 92A1 - Adds the following to the 92FS: Internal recoil buffer system, railed frame, rounded trigger guard and a dovetailed front sight. Made in Italy.
• 92 Brigadier - Identical to the 92FS except: the slide is heavier and has more material ("wings") around the locking block area, the front sight is dovetailed, and it comes with rubber finger groove grips.
• 92 Vertec - A 92FS slide that has a dovetailed front sight, with a railed frame that has a straight backstrap rather than the standard curved frame. Made in the USA.
• 92G-SD - Brigadier slide, G mechanism (decock-only), night sights, front and back checkering, beveled mag well, railed frame, recessed target crown barrel. Made in the USA.
• Wilson Combat 92G Brigadier Tactical - based on the 92G-SD, but with the following differences: rounded trigger guard, Wilson Combat rear u-notch battle sight, barrel shortened from 4.9" to 4.7", very slight dehorning of the slide, oversized and checkered magazine release, skeletonized hammer, Wilson Combat fluted guide rod, G10 grips, Wilson Combat emblem on the slide and the lighter "D" hammer spring. Made in the USA.
Different models come with different magazines, but they will all accept any magazine made for the Beretta 92. Flush-fitting factory magazines come in 10, 15 and 17-round varieties with various finishes. Mec-Gar makes 18-round flush mags, and 20-round extended mags. At least 3-4 of these models can be had in either Bruniton (Black) or Inox (Stainless) finishes.
Whichever model you get, the "D" spring is the best $5 modification you could ever make to a gun, and get yourself some 17, 18 or 20 round magazines. Don't let anyone tell you the Beretta 92 "only holds 15 rounds". Not anymore, people. And seriously look into a G model. The biggest complaint from most people about the 92 is the safety, and how it can be unintentionally swiped down during slide manipulations. The G models eliminate this problem.
If you buy it brand new, disassemble and completely clean off all factory grease. Drop a healthy dab of oil on all critical parts, then shoot the crap out of it and enjoy one of the most reliable and best-looking semi-auto handguns ever made.