Having ordered Lacuna recently, I got excited with the Spy genre.  The only other one I know is Cold City (which happens to be a damn cool game by the way).

So tell me folks, what other cool spy-themed RPGs are there ? Which one you find the best and why ?

Not many I know of. Victory Games 007 RPG remains a classic, and Top Secret, while not as revolutionary, was a solid game that enjoyed a long popularity and deserves a shiny new edition. There was a Fate game about swinging groovy retro spies in the " we're only slightly more serious than Austin Powers " vien, but it didn't appeal to me enough to read it. I think it's a genre that has yet to have an iconic rpg implantation ( Top Secret filling the position by default more than anything), and I'd be interested in a game that took a serious ( well, at least action movie- serious) approach, without delving into the well-tread Xfiles territory.

There was a D20 game line called Spycraft that I avoided like I avoided all D20 games at the time. Don't know much about that one.

It's not a genre I've really played... but here are some other suggestions:

Covert Ops is still in playtesting, AFAIK. Uses a system variant of DWD Studio's Barebones Fantasy Rpg.

Mercenaries, Spies, and Private Eyes is an old one from Flying Buffalo.

Spycraft 1e was a solid d20 game (much better than d20 Modern), but it was a sprawling game over a lot of books.

Spycraft 2e was an excellent modern action ruleset, also d20-based.  However, it was very heavy in its rules, and I found that the rules didn't add to the fun after running it for quite a while.

I considered Leverage as a faster-paced alternative, but there wasn't enough dedicated genre support for me.  I don't know if the new Cortex Plus Hackers Guide would help with that.

I think GUMSHOE's Night's Black Agents is an excellent game for doing spies.  I used it to good effect and excised the vampires out of it and played it straight.  The announced supplement for it sounds like it will add a lot more good stuff.

There is an OSR 007 game out there.  That was a good ruleset back in the day.

I'd like to know more about Disposable Asset; I suspect it's too story-driven.

The FATE game mentioned above was OK.  I too hated the groovy take on things.  I think there was another FATE spy game out there also.

There was a Savage Worlds game out there that mixed spies and the supernatural.  If you don't mind Savage Worlds, it was pretty good setting, even if you cut the supernatural out of it.

I love the genre and always want to play it, so I hope this helps a little.

For historical source material, the two-volume Covert Operations Sourcebook in TSR's Top Secret: SI line is excellent regardless of whether one uses the TS:SI rules set.

The original Top Secret also has some handy bits as I recall, especially for Cold War era games, if you can get it at a price you won't regret even if you find the whole nine yards not your cup of tea.