So yeah, this is pretty much the greatest game EVER so far. When Fallout 3 came out, as much as I loved it, I felt like there were some gameplay and thematic contrivances made in the transition from Fallout 2. Things that made the world feel more "real".
New Vegas has basically returned EVERY aspect I loved that was lost from Fallout 2, and added spades more.
I was not expecting this, I didn't know how much of the old Fallout Obsidian would retain into NV. And it is spectacular.
Starting off with character creation: Traits are back, there are 10 (i think) you can choose from to start with, and each carries with it a bonus AND a penalty, so there's no unbalanced "uber combo". You can also choose to not go with any traits at all, if you wish. I went with "Four Eyes" that gives me +1 perception if I am wearing glasses, but -1 if I'm not, and "Wild Wasteland", which increases the odds of unique encounters both good and bad. They've also revamped the skills; I had posted earlier in this thread about eliminating "Big Guns", consolidating all ballistic weapons into "Guns", and then shuffling flamers to energy weapons, and rockets/grenade launchers to explosives. This opens a slot for the return of "Outdoorsman" skill, which factors into cooking/crafting and survival.
Lastly on the stats, they've returned to the original perk system, rather than doling out perks every single level, you only get one every other level. This definitely makes the perks feel more special and meaningful. They have also completely eliminated all the "points in skill" perks, ones that only contributed points to one or more stats. Any seasoned Fallout 3 player knows those perks were completely worthless, because the exp system in the game grants you more than enough skill points to max out all the skills you'd need for a powerful min-maxed character. If you were persistent enough you could even max out EVERY skill to 100 in Fallout 3 without any exploits. Now every perk serves a purpose, so you won't feel that regret when you realize you didn't need to pick that shitty perk that only added 5 points to guns and repair, or whatever.
Crafting plays a HUGE role in the game now, not just limited to 6 or so oddball weapons you could make like in Fallout 3. Now you can make food, more powerful chems (think Jet with double the potency, super stimpacks, etc), and special ammo types. You can even break down ammo you collect and then reassemble those parts into different ammo, so you're not stuck with "worthless" bullets for a weapon type you don't use. You start out with a sizeable amount of recipes, but you find more as you gain perks and quest as well. You can also make special traps, weapon repair kits (so you don't need the same weap/armor to fix your things, great for those hard to find or unique pieces), and many other things.
Food is MUCH more useful now. In Fallout 3, any type of food, prepared, raw, or scavenged junk food, was basically worthless for healing compared to stims. At most you'd get 15 or so HP, and a nice dose of rads to go with it. Now food carries a heal-over-time property, and cooked meals can regen a VERY sizeable amount of health, as well as provide other buffs. Also very important if you're playing hardcore mode, because stims do not heal instantly, they have a heal over time property as well, so stacking that with food helps a shitload, while also staving off debilitating hunger pangs.
The gunplay has had a big overhaul too, with "true iron sights" being added. Basically you get to ADS just like in any COD-type combat game now. The guns also feel more responsive and accurate too, with the game being VERY clear on exactly what the repair status of a gun means towards its effectiveness. This makes normal (read: non VATS) combat a reasonable and fun way to play the game, a great change of pace from Fallout 3. One thing that did bug me is there is a "cinematic kill cam" mode thats enabled from the start. This means that randomly, when you get a crit in normal combat, the game will pull out to a 3rd person slo mo view and show the impact. This can happen CONSTANTLY if you build your character towards crits and it slows down combat tremendously. Luckily you can disable it, and i strongly recommend doing so. It has no effect on the VATS killcams, so you're not missing out on anything.
The weapon variety is excellent, another callback to the old games. Instead of having just one or two weapons in each category, there's TONS of options, lots of different handguns, rifles, shotties, etc. And you can add custom mods too, extended mags, scopes, and the aforementioned ammo types. It just helps to make the world feel "bigger", less repetitive.
Finally, HARDCORE MODE. I feel this is the way you should be playing the game. Stims don't insta-heal, so you can't jack the button in an emergency and survive ridiculous encounters. You suffer from hunger, thirst, and sleep deprivation (although these are easily managed with food if you're attentive, just like real life

) Ammo has weight so you can't carry 50 mini nukes with reckless abandon, so every chest you loot is a tactical decision on what you actually scavenge. And you can't heal limbs with stims, you need to use a "doctor bag" item, or visit a doctor to repair them. Resting doesn't heal you to 100% health either. This is the "real" wasteland experience, and I
fucking love it.If you missed the bandwagon on Fallout 3, don't skip this. Its got its own story and setting, so you won't be "lost" not having played the previous games, but if you have, then there's a GRIP of nostalgia and fanservice to be had. And if you played any previous Fallout and enjoyed it, you owe it to yourself to get on New Vegas as fast as possible.