Asok is correct Kev - The River is a superior (double) album. Again - the sound isn't great on the original but the songs - oh yeah. The Live from New York City show contains many songs from the River BTW.
Nebraska is a mixed bag for someone who is still not sure he is a Bruce fan. It is only acoustic - Bruce and his guitar (no E St Band) and it is very bleak and depressing. That said - it is right up there with my favorite Bruce albums.
Personally - I think the next experiment for you would be Live 1975 - 1985. It's a 3 CD set and it simply kicks ass. As a bonus - most (not all) of the songs from Nebraska are played with the E Street Band on this collection so it's a great introduction with the Nebraska songs sounding much more upbeat than on the original.
Check it out here - with the reviews and song samples. If you ask nicely

- I might even send you a track or two.
Bruce Springsteen & The E Street Band - Live:...
In the US - the shows are seated with the floor being the GA tickets so you can go either way. Do NOT think that you will get to the front of a Bruce show though. The rabid fans who have been around for 35 years will show up days ahead of time and even bribe the cops to keep a front row place.