I would like to take advantage of the www.gog.com holiday sale but only want 1 for now so what would you recommend I get first fallout 1 or fallout 2 and any differences besides story?

edit: will be buying tomorrow or the day after.

It depends... IMO Fallout 1 is better than FO2 (in general), but FO2 has very specific fixes that FO1 lacks (and needed)... and FO2 a larger game over all.

If you will only play one of them... Play FO1. It's got a better story and atmosphere; shorter game though. FO2 is better IMO when you have already played FO1 through to the end.