What? HTML Can be fun? Well, kinda. Here's a few codes that look cool..ish.

Marquee

Oh, wow. The marquee. I think you know what it does. Example: This is an example marquee!!!
The code:

<marquee (optional)width="WIDTH IN PIXELS" height="HEIGHT IN PIXELS"(/optional)>

Yeah, anything between the (optional) and (/optional) are completely.. optional. o.O Delete anything inside the brackets and including the brackets, however.

Fieldsets

Just an example of a fieldset:

The code:

<fieldset> <legend> Fieldset Header </legend> Fieldset Text </fieldset>