If you were a fan of always having the same friends showing as your "Top Friends" on Myspace, but bailed on Myspace like everyone else, because it got too lame, don't fret, there's a way to do it in Facebook too! Setting your Facebook top friends will also have the added benefit of keeping them in an easy place to click if they're the same profile that you regularly visit, you just load your own page and the same top's will always be there.
One thing to note, Myspace's Top Friends gave you the choice of keeping your top friends always in the same order, or having them randomized everytime the page was loaded or refreshed. Facebook's top friends only randomizes; no option to keep the same people in the same place all the time, i.e. you can't always have STaRDoGG as your #1 (top left).
Let's get cookin' shall we?
Load up your main profile page, (not your "home" page, but your actual profile)
Look down to the lower left-hand side at your Friends box
Click the little Pencil icon in the Friends box
Below where is says "Always show these friends" start typing the name(s) of the friends you want to have as your top friends, who you want to always show up in your friends box
(Optional) Where it shows the drop-down arrow saying "Show X friends" you can select how many friends will actually show in your friends box
When all done adding all of your top friends, just click outside of the box somewhere, like a white spot on the page
For a visual reference, see the screenshot below
Unfortunately this doesn't work on the new Facebook profile that came out a couple days ago.