The closest you've gotten to clearing the national dex

I cleared all 151 for the first generation, and I tried to do the same in 2nd... but I gradually stopped caring when 3rd gen came about.

For 4th gen (when I get it), I probably won't try to "get everything" and strip & kill my previous games by doing so.
I ended up with nothing but Pidgeys on my Blue version!

FireRed: Caught: 171, Seen: 349
Emerald: Seen: 381, Caught: 381(all but Mew, Celebi and Jirachi)
Diamond: Seen: 493, Caught 493
Platinum: Seen: 352, Caught 64

I don't own all 493 Pokémon though, Celebi and Mew are still missing, though HG/SS will probably fix that.

Also:
Total: Seen: 495, Caught: 493
Because Zorua and Zoroark need some love too.

Only one game per "set" even though I have more than these.

Pokemon Yellow - 130/151
Pokemon Gold - 249/251
Pokemon Ruby - 99/386
Pokemon Leaf Green - 61/386
Pokemon Platinum - 302/493
Pokemon Soul Silver - Progress

Just bought a new charger and SoulSilver yesterday, so I've finally been able to play my DS for the first time in over a year. Might as well pull out Diamond for this since it's the game I've accomplished the most on:

Diamond: 325/492 (Caught) 419/492 (Seen)

Not as good as others here, but I'm pretty proud. 105 hour play time so far, though I don't plan on playing it much now that I have SoulSilver.

I killed the Hoenn Dex.