All 7, ordered by launch date (going off the top of my head, feel free to correct):

snopes.com (1994)

gamefaqs.com (1995)

archive.org (1996)

wikipedia.org (2001)

tvtropes.org (2004)

openstreetmap.org (2004)

github.com (2008)

I really think they encapsulate the best of what I like about the internet. I've been formulating this list for quite some time. Limiting to just 7 keeps things interesting! For example, it's a pity steampowered.com had to be left out but I see it less as a "website" proper. I wonder (ha) how my list differs from everyone else's.