It is tough to go in comparing games that are generations apart. The mechanics and way games were designed in the 90s and early 00s is just different. There was generally a lot more freedom in those games but also a lot less to immerse you and there was less polish. I love Fallout 1 and 2(I suggest going back and playing with the restoration mod if you haven't) and I also love Fallout 3 and New Vegas. I really don't consider them as one in the same. Fallout 3 and NV are really just spiritual sequels in my eyes. I have the same feeling with the new X-com.
That said, if you are just getting into the new Fallouts I suggest starting with Fallout 3 before going to NV. While NV is better, Fallout 3 is a great experience and should be enjoyed before spoiling it with the(IMO) better features of NV.
That said, if you are just getting into the new Fallouts I suggest starting with Fallout 3 before going to NV. While NV is better, Fallout 3 is a great experience and should be enjoyed before spoiling it with the(IMO) better features of NV.