I've never been able to replicate that experience in another game.
Someone tried to clone it but never took off: http://www.projectstealthgame.com/
Best wishes to OP for the game and (at least) giving me fond memories.
The only thing is that, like quite a few games today, it was best in beta. I distinctly remember that in the final version, they tweaked the lighting model across all levels to be far higher contrast, and that pretty much killed it for myself and everyone I knew who played it.
Yeah, you couldn't cheat anymore by turning up your gamma, but that came at the price of destroying those priceless moments where you thought you saw something in the shadows, but you weren't sure.
One of my favorite bits of SC:CT is the "are you a ninja?" dialogue.
One of the developers for Splinter Cell, in his spare time, helped out with the project and probably benefitted tremendously from all the multiplayer testing and balancing we did.
At some point he asked all the team members for our real names and put us in some of the communications documents/emails in the actual game. It's really odd to see my name pop up in GameFAQs walkthroughs and such, and perhaps a bit depressing to know that it's what 'my name' is most famous for. But mostly fun.
I never played the SC multiplayer, but Thievery:UT has been some of the most fun I've ever had multiplayer, more than all the UT, Quake, Age Of Empires, and whatnot.