I think you'll be able to tell I like Geocities the best.

Geocities
As you can tell, I love Geocities. Lots of people don't like it because of that annoying little ad in the corner. But a simple html code takes care of that. Other then that, Geocities is great. It has a page builder for beginning site designers, and an easy to use file manager.
The only pop-up is on the very first page. All the other pages are pop-up free. I like Geocites. It also protects people from direct linking your images.

Tripod
I really don't recommend Tripod. Losts of people like it, but I don't. I guess its good because it's easy to use, and not hard or complicated. But I don't like it for one reason: the pop-ups.
This server goes crazy with pop-ups. I can accept one pop-up, but FOUR? I honestly think that's too much. And the problem is that as soon as you've closed two of the pop-ups, the other two pop-up, and then one is hard to close.
But Tripod is pretty good, and it's easy for beginners.

Angelfire
Angelfire and Tripod are by the same company, but, Angelfire is better. The down part is that you have to be 18 or older to make a site without permission, while with other site builders, it's 13. But, Angelfire is good. It's easy to use again, and it's prety flexible. There's only 2 pop-ups. But what I hate here is the banner at the top of the page.
That banner is so annoying! It drives me crazy! Its flashes around, all distracting and everything. But, other then that, Angelfire is a good pick.