if you would notice most of the modern games are either war games, or games like gta. im just at a loss for how you are going to do an urban fantasy similar to one of those games.
loss? *Sigh* Bioshock uses magic hidden as science, Mass Effect in the 21st century, Call of Duty with magic as additions to your arsenal (aka Legendary except done properly)... Even The Bureau: XCOM Declassified's game system (third person shooter with slowable turn-based elements) would work since they employ a class based magic system. Or better yet, something using the XCOM engine! Do Ogre Battle: Tactics in a modern setting! Cross-over Fire Emblem and Advance Wars! Something! Anything!
i just dont feel like taking a war game and tacking on magic would do the modern fantasy genre justice. if anything look at la noire or mafia for gameplay inspiration. the problem i have with using xcom and bioshock is they are both apocalyptic settings. i feel like something like a mafia setting featuring a dispute between factions say seelie and unseelie fae courts ala lost girl could work.