Downloading 200MB Windows 98 update was the adrenaline back then.

For me it was downloading mp3 files and only letting Winamp play them on repeat as they download. At first you just got a second or two of sound, and it would add maybe a second on each play. Eventually the magic of compound interest would get you the whole song, and that was a major adrenaline rush

I remember downloading IE4 over a phone line at the inlaws. It took hours for a few MB. It was worse if I recall as I already had broadband via Road Runner back then (1998).