If it's nostalgia caused by music then I would say for me it would be:
http://www.youtube.com/watch?v=6vaBx...=youtube_gdata
&
http://www.youtube.com/watch?v=iCP8Y...=youtube_gdata
Even though this next one isn't from an 8-bit game it brings nostalgia for some reason (probably just the sound).
http://www.youtube.com/watch?v=c6jjC...=youtube_gdata
Edit: attempting to fix the links, damn my phone for not being able to copy and paste.
Edit2: that should do it. I had to change the link for the last one, which is a shame since I liked the picture on it.