You'll like them. Fallout 1 takes a much more serious approach to the story telling, it's a gritty world that is very unforgiving and is much like Morrowind in that respect. Fallout 2 is more like a monty python show in the fallout universe, I like comedy so I LOVED fallout 2.
Both take a while to really get going, Fallout 2 especially. But when you get guns (at least for me, this was the turning point) things start getting a lot more fun.
Like any old game though, it's clunky, ugly, dated and makes references to the 80s and 90s. But if you can work with that, they are pretty much pure gold and I still sink time into them every so often. Like Therm said though, get the patches, makes the game a lot better. I don't play with them, but that's because I played them on a windows 98 computer and didn't 'need' the graphics patches. Have fun!