I got 110/151. Like many others, my brain just froze and I couldn't think any more names. I remembered all pokemon to number 40, but the poemon with bigger numbers were harder. Now that you look at the names I missed, I feel so stupid I didn't remember them. I can't believe I almost forgot Eevee & evolutions! (Remembered them during the last minutes.)
EDIT: I tried the 2nd generation too, and got 73/100. I remembered Wooper and Quagsire at last seconds and didn't have time to write them. :P Also, Jumpluff is the first pokemon whose name I couldn't remember even though I remembered the other evolutions. But this was propably it was during the last seconds, too.