1993-1995: Mostly scientific & technical papers & discussions. Deeply intellectual, with almost everyone on the Internet having a professional background and many being top experts in their fields. The WWW was a relatively minor protocol on the Internet; much discussion still happened over E-mail, Usenet, and Gopher, and Telnet and FTP had as many sites up as the WWW. (Although fact-checking my memory, apparently AOL opened up Internet access in September 1993 and that was the beginning of an influx of kids - like myself - onto the Internet, which is what started degrading the Internet.)
1995-1998: AOL's Internet access was in full swing, Yahoo and Geocities were founded, the trivial "fun" usages of the Internet started to overshadow the scientific & technical ones. This was the era of WebRings, Geocities pages, <blink> tags, garish colors, and sites that looked like they were made by a 12-year-old because they probably were. Lot of band pages, fan pages, joke sites, and trivial pop culture. First Internet advertisements started to appear.
1998-2000: Dot-com boom heyday. Peak gold rush. The dot-com boom is normally dated from 1995-2000, but it massively accelerated in 1998 after the Amazon & E-bay IPOs, resolution of the Asian Financial Crisis, and drop in interest rates. This was the era when VCs were throwing hundreds of millions of dollars at ideas on napkins and then taking them public 3 months later. Most activity was centered around E-commerce, where the belief was that an online version of every retail sector would take over and dominate (which turned out to be true, but happened 20 years later with Amazon).
2001-2004: Dot-com bust. Many pundits declared the Internet over, though anyone looking around could see that wasn't the case. Most of the big VC-funded companies founded in 1998-2000 went bankrupt, thousands of people lost their jobs, many people get out of the field entirely. People talk about how all software engineering jobs will be outsourced to India. Microsoft "wins" the browser wars with IE6, and also has heavy adoption in the server (NT Server + IIS), database (SQL Server), and programming framework (ASP.NET) areas. Enterprises start moving their software to the browser. Consumer attention is largely focused on P2P filesharing (Napster, Kazaa, Gnutella, Audiogalaxy, etc.) and on early proto-social-networks (Xanga, LiveJournal, EZBoards, 4chan, Friendster, MySpace).
2004-2008: Social networking boom and return of Web 2.0. Facebook kicks it off in 2004, along with the acquisitions of Blogger, Flickr, and Del.icio.us (all of which had been steadily building throughout the bust) and then in rapid succession we get Digg, Reddit, YouTube, and Twitter. At this point the corporation names start getting recognizable, so I'll stop there.