Cleaning email archives over the weekend, came across emails from my first email account on usa.net in 2000 – the first time I got access to internet (though I had access to a PC since 1993 I believe – MS DOS, no HDD). Took me back to exploring my firsts on internet and here is list of what I can recall –

Service First Used
Email Account usa.net (@netaddress.com) (2000)
Chat service Yahoo Chat (2001)
Search / Directory service Yahoo Directory (2001)
Blogging Blogspot (2004-05)
Streaming (audio) Yahoo Launchcast (2004)
Streaming (video) YouTube (?)
Internet Banking ICICI (2004)
Online Shopping deals2buy.com (2004)
Social Media Orkut (2003)
Cloud Platform AWS (~2010)

Will add if I recall any others.