I got Fire Red up to about 375. The only things missing were Leaf Green-exclusive Johtos, the Totodile line, Ho-oh/Entei/Suicune, and unobtainables.
I've never gotten bored enough with the GenIV games to even bother filling the National Dex. I should probably go do that on one of my games, probably Pearl, so that I can properly patrol the GTS for bargains.