I've still never played fallout 3. I know some people here said it's not really worth playing in comparison to NV, but I've also seen some nerds elsewhere say F3 is way better than NV. I've read a little about it, seemed a little depressing but not in a good way
I never really understood why these games were that polarizing, personally. I definitely got more out of New Vegas, but Fallout 3 did enough things right that I'd call it worth most people's time. To a degree I feel like it comes down to whether you want more exploration or more narrative. For me, Fallout 3 was more about just going out into the wasteland and getting lost doing stuff, while New Vegas was more about storytelling and these tense relationships between all the people in the world.
If you can handle more Fallout after finishing New Vegas, it's probably worth a shot. It's not really the same, and can get insanely boring just hiking around for no apparent reason, though you can always just stick to the main story and skip all the unnecessary shit. Since you liked New Vegas, I'm guessing you dug the narrative, so you kinda need to expect a whole lot less of that in Fallout 3. Does have its moments, though, and the DLCs are actually pretty worthwhile much in the same way they were in New Vegas.
I think all of NV's 4 DLCs were great additions to the game, really the only worthwhile DLC I've ever seen
I have to ask, since I completely missed this when I went through Honest Hearts: Did you read the
Randall Clark diaries? If not imho you should read them, even if you're just looking at it on that website. There's some pretty neat storytelling in the Fallout games, but I don't think anything else in those games really comes close to that.