A couple of general toy sites that have/had Transformers stuff:
http://www.toyarchive.com/ is still up, but it also still has webrings
(I still check things on this site every once and a while)
an archive of toys from the 70s, 80s, 90s, and 00s
web.archive.org
Oh, that's another I remember! First place I found any photos of Diaclone figures, IIRC. And a variety of images of some of those legendary Japan-only Transformers I had only read about... Among other things.
(Did I mention that some Transformers fan meets were the first time I had any idea what certain Transformers figures actually looked like, even with the various fan websites about? First meeting I went to, the host had a combined Victory Sabre in his home office, which was an amazing sight. Yes, I said fan meetings, as dedicated Transformers conventions didn't exist yet in the UK.)