Some trends are meant to stay in the past. These web design trends of the 1990s were the driving force of 90s websites, but should never surface again. Read them and never include them in your designs.
Do not ever include animated gifs in any aspect of your website. They are cheesy, have huge file compression issues and produce the poorest quality animation on the web today. Flash introductions/splash pages on your website should also be avoided. Sure, it might seem cool the first time, but it quickly because nothing but annoying when visiting the site repeatedly. Further more, 100% Flash websites should not exist for any business trying to rank on search engines like Google. They can still be found today, but anyone that cared about SEO and keyword density has moved on long ago.
Lastly, ditch the floating menus and the custom mouse cursors.
Because, seriously you guys.