Have You Played? is an endless stream of game recommendations. One a day, every day of the year, perhaps for all time.
Counter-Strike became so popular so quickly - even the mod was soon bigger than all retail multiplayer shooters combined - that the entire industry seemed to spend a year or two simply producing similar games. Remember Global Operations? Remember Strike Force? Remember Tactical Ops? I do, I played a dozen of these, and Tactical Ops for Unreal Tournament was probably the best of the bunch.
What began as simply adding realistic weapons to Unreal Tournament-style maps slowly transformed, iteration to iteration, into a more robust realistic experience. Eg, it added maps with lots of shipping crates. It also retained some of the physics of its base game, but those were already a more natural fit for this kind of game than Quake 3's physics were for its equivalent mods.
Otherwise it didn't stray far from its inspiration: it was round based; there was a buying phase for picking up weapons and armour at the start of each round; you collected money for downing enemies; and there were objectives such as planting bombs and rescuing hostages; the mod eventually received a retail release in 2002.
I struggle to remember now why I put so many hours into Tactical Ops when I could have, would have, been playing Counter-Strike so much already, but I have strong memories of doing so. Mostly while watching new episodes of Buffy the Vampire Slayer on BBC 2.