I use some star was minis. I also use some little plastic figures from gumball machines -- homies. There are tons of them, but they sure give the game a slightly hispanic spin.
A lot of my stuff is pretty old -- Ral Partha's "Vampire" line gave me a bunch of great civilians. But there's a lot of other options.
The Superfigs line has two packs of innocent bystanders.
Wargmes Foundry has a line of (expensive!) modern miniatures, called "Street Violence". Really good stuff.
Rafm has some new miniatures that are intended to be modern adventurers...and some of them will look very familiar, too.
(Look under the Cthulhu figures, for Modern Day Heroes.)
But best of all, there's Copplestone Castings. The "Future Wars" line is very near-future, for the most part, and the sculpting is simply incredible. They paint up beautifully, too.
Fiery Dragon put out Counter Collection 3: Modern and Counter Pack 4: Eldritch Horrors & Occult Investigators way back in the day. You can still buy them in pdf format at DriveThruRPG, or included in Counter Collection Digital (available in CD format).
WizKids various 'Clix based games have a few modern pieces that are good for NPCs especially, things like cops, medics, etc. There new game HorrorClix is going to feature "victim tokens" which are classic horror movie characters. I'm a bit disapointed in that I was hoping they would be actual minis, but they migh work. Of course they aren't coming out until August. The link has some samples of both monsters and victims.
I acquired a product called Cardboard Heroes from Steve Jackson Games. It took a little time to cut out and tape the figures, but now I have enough for most situations in a Modern game.