I've never played any Fallout game except for 3. I only bought it because I was a huge Oblivion fan and I figured it would be very similar. I know that the other games are structured differently, but I'm wondering if it's worth it to play the others. Any suggestions? Would I like the other games given that I like 3 so much?
It's definitely worth it to play the others... But be warned that they aren't remotely like Oblivion.
It kind of depends on why you like 3. If it's just the huge exploration aspect, you'll probably be disapointed. Fallout 1/2 have far fewer places to visit. However, most of those places are fully fleshed out, with multiple sidequests and other interesting things to do.
If you like it for the real time combat and/or first person "immersion" factor, you won't like the originals either. The originals are immersive because of their rich dialog, humor, and details, not because of graphics. Also, the combat system is turn based, so if you think that's boring, you might as well not even bother.
If you like FO3 for its story, you'll probably like the originals. FO3 borrows most of its plot points from the previous two games, right down to the ultimate goal and the antagonists.
the graphics are basic by today's standards, to say the least.
There is, however, a certain charm to them. Especially in the bloody mess kill animations. FO1 and 2 has even more death animations than FO3 does.