New Vegas has more style, better quests, and is better written. Honest Hearts and Old World Blues are stellar DLCs - whereas I only liked Point Lookout for the Fallout 3 DLCs. Both are pretty good games, but if I have to recommend only one, it's easily NV.

Love them both.

FO3 has on its main quest more of a tug at the heart story; and basically modernized Fallout franchise in numerous ways to work as a modern-day type of open-world RPG (and it felt extremely fresh and new). FO3 was also a lot more serious in tone, when compared to FO1+2. FO3 has more of a destroyed look to it, as well - especially when compared w/ the other FO games. Also, FO3's Main Story also deals w/ "water supply problems" and "finding the GECK" seemed like it was also aiming to pay homage to the great FO1+2. FO3 is the first major FO title to put the game on the East Coast, BTW. Since FO3 is a BethSoft game - its writing and companions are often nowhere as great as what FO:NV did w/ it.

FO:NV took the modernized gameplay of FO3; brought the ultra-strong and technically strong narrative, dialogue, & characters that Obsidian and Chris Avellone are often known to create; and the witty humor and quirkiness that both FO1+2 had. While FO:NV was destroyed and in ruins, it's nowhere to the extent of destruction that FO3 had going on. Plus, FO:NV has a lot more color in its palette, when compared to FO3. FO:NV's main story is not really as heart-tugging as FO3's "Search For Dad", but it's definitely technically much stronger and much better put together. Also - NV takes place on the West Coast, just like FO1+2.
Also, FO:NV has Old World Blues - probably the best DLC that I've ever played.

I can't see why anybody would avoid either FO3 or FO:NV. Both are excellent, in their own ways. I've spent over 100 hours w/ each FO3 GOTY + FO:NV Ultimate. You absolutely can't go wrong with either title. Play 'em both - but, since they are HUGE time-sinks, you'd probably do yourself a disservice if you played them back-to-back - b/c they're both very similar, in many ways. Spread 'em out a bit, I say.

Fallout New Vegas is the better game for me. I enjoyed Fallout 3 but getting past the nice new visuals and fully realized 3D world I felt the narrative and roleplaying experience and characterization of NPCs was somewhat lacking by comparison to Fallout 2.

Fallout: New Vegas readdresses these issues for me, it's not a perfect game but it harks back to the glory days of Black Isle. I enjoyed it a lot!

If you can, play both but if you've only the time to play one then I'd go for New Vegas.

A galaxy's worth of mods and extras means there's a lot of replay-ability and customization to be had with both games.

I can, but as I said, it was mostly related to the massive clusterfuck of a bugfest at the very end that made New Vegas resemble an ant farm more than a game. This is the wrong topic to elaborate and go all spoilery on people, I think.

Thanks for the replies but TLDR, gonna play Doom3 BFG instead.

Later, losers.

I didn't have neither.

Then a friend bought me New Vegas as a birthday gift.

WHELP.

I got both FO3 and New Vegas in the Steam sales. Not sure when I'll get around to playing them, but does anyone have any must have mods to run the games with? Not looking for mods that'll change the game entirely, but ones that will make improvements to the clunkier parts of the game, just to add enhancements and such.

My thoughts exactly.

Anyway, the topic:
Both games have their strengths, but it's obvious that Obsidian could put more effort into gameplay and storyline because they had most of the engine and assets work already done and didn't need to start from scratch. Anyway, seeing as you can get them both for cheap these days, even with the DLC which put a lot of extra value to the games, I'd recommend to start with F3 and then moving on to F:NV.

Here you go

For Fallout 3

Graphics & Models
NMCS Texture Pack - http://fallout3.nexusmods.com/mods/12056//?
Fallout 3 Redesigned Better NPCS - http://fallout3.nexusmods.com/mods/6341/?

Quest Mods
A Note Easily Missed - http://fallout3.nexusmods.com/mods/4730//?
An Evening With Mister Manchester - http://fallout3.nexusmods.com/mods/5630//?
The Institute - http://fallout3.nexusmods.com/mods/14449//?
To Sleep Perchance to dream - http://fallout3.nexusmods.com/mods/6921//?
In the Shadow of the Swamp - http://fallout3.nexusmods.com/mods/7268//?
The Mantis Imperative - http://fallout3.nexusmods.com/mods/12296//?
A Devils Wish - http://fallout3.nexusmods.com/mods/18572//?
Alton IL DLC type twice the size of point lookout - http://fallout3.nexusmods.com/mods/16949//?

User Interface - MTUI - http://fallout3.nexusmods.com/mods/43//?

Maybe those people are just not as vocal. I played Fallout 1 and 2 and I liked Fallout 3. Maybe it's because I did not have fixed expectations that needed to be fulfilled. I also like Oblivion, which may be related. I did play FO3 with quite a few mods though - most notably Wanderer's Edition, I guess, which is a overhaul of many aspects of the game. Since Oblivion, I always wait for the GOTY and the overhauls that are invariably created.

DC is a much better environment to explore. Also, progress does not necessarily have to follow a curve around the map like the rather blatant one in NV, which does make it a fair bit more linear until closer to the end.

Other than that though, yes, NV is the better game.

Yeah, that "U" thing in Vegas was kind of annoying. I'm surprised that they didn't just stock the place with uber strong beasts that yielded negligible XP rather than preventing people from traversing certain areas.

I liked both, they each have their own charm. Am actually working my way through F:NV right now, and thoroughly enjoying it. Like you, I found/find F:NV a little bit more buggy for sure. (Yeah, gotta love good ole Liam)

Alright I can't really disagree with that, but the DC area did have way too many boring subway tunnels.
Other than that it was quite well designed.
And I do like both games a lot and I feel the many differences work in their favor.