Things New Vegas Did Right/Improved On
Gameplay
Main Story
Amount of Weapons
Number of Places to Explore
Referencing Old Games Correctly
Amount of content
Things New Vegas slipped up at
Twisting your arm to get the main quest finished
Things New vegas did that made me angry personally
Bug testing
The dlc content was cut from the game
I'll explain my reasoning on a few, first nobody can argue that new vegas was the better game, gameplay wise. Saying it had lots of stuff to do was an understatement, as it was full of content.It also expanded on the old games which as a longtime fan I thought was pretty cool.
However there are some minor qualms that I have with it. Such as there never being a good place to start exploring If you go north at the start of the game you die, so it forces you to go around the loop. Which is a bit of a failure on their part, because the designers have gone on record stating that they wanted you to explore the second you started the game, hence they cut out the heavy intro sequence ala fallout 3.
There are two things that really made me mad as a gamer, they bug tested horribly, and the final product is the most buggy game I've ever played. Also the dlc was cut from the final game, HDIK? Because of one thing, in the collectors edition you get a card deck, and guess whos in it? Ulysses, a character extremely important to the backstory of the courier. That means the developers thought they were going to release a full game and at the last minute bethesda cut the content, because they wanted to make money off of dlc.
tl;dr Its a better fallout game than fallout 3, but fallout 3 is a better videogame than new vegas