Hmmm, first adventure game ever? I don't think there WERE any adventure games as such on the Sinclair Spectrum *feels old*. So I'd have to say the first adventure game I remember playing was the original Space Quest 1.
I loved it. The humour was spot on and the story was pretty good too (compared to other games I'd been playing like "Castle Master" et al). A great introduction to adventuring.
P.S. Hello all! *1st post newbie"