Although I like both games, the edge goes to FO:NV. NV strong points:
The true-iron sights just makes shooting from 1st person far superior.
The faction system is superior - you can join various groups.
Throwable weapons (spears, knives, etc. - both games had grenades)
Crafting system (reload your own bullets, recharge your energy cells, or create campfire recipes with various effects)
Hardcore mode (optional - heal damage over time, you must eat, drink, sleep)
Different endings (at least 4)
Companions (with quests)
Better quest-lines.
Gambling mini-games
If I spent more time, I could probably come up with other reasons, but you get the idea. (NV does have a western feel, may be a draw-back if you don't like that type of thing - but I didn't think it was that big of deal)
I'm currently in the midst of a NV playthrough (got the game and all dlc for $14 during steam sale) and I'm enjoying it far more than 3. Pretty much what Rune said, as well as far more guns and equipment. In 3 it was kind of annoying that the only viable armor later on was power armor, but in NV you've got light, medium and heavy (I've always been a medium fan myself).
Fallout 3 feels much more original. I have a very good feeling whenever I think about playing it. It's completely unique. NV makes many improvements on the gameplay and other mechanics, but that's traded off for the game not feeling so apocalyptic. New Vegas feels weird in that way- it's too close to home.
Gotta hand it to Bethesda when it came to the environment in FO3. The Mall section was my favorite part by far. Nowhere in NV is there a place that comes close to the grandeur that was the Mall. God, I love that place. The cities in FO3 where so creative and original - Megaton, Rivet city, Republic of Dave. Goodsprings, Primm . The only ones that are half creative is the 188 Trading post, and Freeside.
FO3 actually felt like a post apocalyptic world, unlike FNV. The ambiance that was created from that dark and gritty scenery indicated was the need for survival.
The only thing I feel NV has over FO3 is the true iron sights. Gambling was fun but it's not a biggie, and certainly not something to hold FO3.
Oh! I almost forgot! THREEEEEEEE-DOG!!!! Best radio-host/dj EVEEEEEER. Mr New Vegas has got nothing on him. Cant touch this! Hammer TIME!
Fallout 3 ofcourse. I liked the enemies you encountered there so much more than in New Vegas, where you only had Fiends, Cazadores, 2 mutants at most, and faction soldiers, that was pretty much it.
Fallout 3 made you kill huge amounts of Super Mutants, with the Behemots as the cherry on top of the pie, Ironclad Enclave soldiers, lot of ghouls, lots of molerats and raiders, and many many more cool enemies that F:NV lacked.
FO:3 also had more interesting environments and I must say that people who find the battle for Hover Dam better than the Battle for the streets of DC with Liberty Prime are totally crazy.
FO:3 had better DLC's if you ask me, only Dead Money and Old World Blues from F:NV where good, while FO: 3 had Broken Steel, Operation Anchorage and The Pitt, with Mothership Zeta and Point Lookout being a bit less interesting but nonetheless good.
F:NV had more weapons and iron sights, yes, and it also had a better faction system. These improvements are however made undone by the fact that FO:3 has a much better story, and mods can add more weapons and iron sights to FO: as well.
My advice, play FO:3 first (maybe add some mods to make it more to your liking), and if you like it, play F:NV for an experience that's a bit different but very good nonetheless.
Again, I like both games, but my preference still has to go to NV. The points that "Ben C" brought up about 3 are well thought out, and it is good that you point out 3's good qualities - they were both really nice games. (Honestly the 'true iron sights' and 'hardcore mode' are the two major wow factors to me in NV). If I may eloborate.
Yes, Good/Evil is more well defined in FO:3, but the good-evil karma really has very little effect on your game in NV; there it is all about which factions - which groups to join. ** Spoilers ** Who cares about running a town? The doc from the town saved your life, whereas the opposing group is escaped prisoners - no brainer to me. But even here you have 3 choices, (1) help escaped cons slaughter the people in a town (which should definately be negative karma - although it has no effect other than your faction choices and making on follower harder to recruit), (2) ignore it, or (3) help the town defend. ** End Spoilers ** In the end, only people that are directly involved with the groups will care.
I agree, FO:3 has more of the wasteland 'feel' and I too prefer the 'environment'. In NV there's only a few places you are reminded that it is an post-atomic war wasteland. You are also correct, your choices of direction is very restricted in NV (although there are ways of making it North - it's tricky, but I can do it consistently now). NV game's direction becomes more open as the game progresses - but you have to progress fairly far in the story before that happens (unless you know some hidden paths), whereas FO3 becomes wide open after the fairly lengthy opening.
And I do agree with your last paragraph, FO:3 has a lot of content and hidden places (and more Easter Eggs). I also light the occassional dark humor found more frequently in FO3. But they're hidden places in Vegas, as well, just not as many.
Not really, just some changes in the vids based on some in-game choices, but the end result is very much the same (except it is possible to 'fail' too). From the wiki:
"Just like the intro, the ending is narrated by Ron Perlman. The first and final parts are the same for each player, the 3 middle parts depend on their choices, Part 4 may not be played if the player... (spoilers)"
So the ending, parts 1 and 5 are the same, part 4 is the same if you succeed. And parts 2 and 3 (vids) vary based on what you did - that's still one ending to me, with minor variations.
The endings in FO: NV (at least four) are much different - you can vary which faction wins. And each of these have variations based on things you did in the game (linked to factions and follower's quest, and we have several of those - with variations on each - but I won't call those separate endings, else there would be dozens (hundreds if we count every little variation) of endings in NV).
** Spoilers ** True, the awesomeness that is Liberty Prime is quite the show to watch, that's what makes it so cool, but in NV you have to kill maybe 20 enemies at Hover Dam and maybe 10 more afterwards at most, that's not much of a bossfight either now is it? In FO:3 you just walk with Liberty Prime who destroys most of what you encounter (many many cool explosions) and you mop up the survivors, in FO:3, your hard work will have given you and your allies true power, you don't have to do all the work again.