"One dinner that I recently did had a dessert with white chocolate ice cream where a stout would be chocolate overkill, so I decided to pair it with Wells Banana Bread beer. Using the ice cream and the beer together created a chocolate covered banana flavor that was a hit with the crowd."—Bill Carl (Southern Wine & Spirits of Hawaii)

"A lot of beer styles won't work for a beer float, but it's fun to experiment. We discovered Lindeman's Framboise Lambic with dark chocolate ice cream to be a decadent treat."—Kendall Joseph (Beer Makes Three)

"An obscure combo I have enjoyed is a Belgian dubbel with rum raisin ice cream. The rich dried fruit character in Belgian bubbels plays well with the rum-soaked raisins. The vanilla in the ice cream brings out the richness of the beer."—Corey Esoldi (Societe Brewing)

Of all the empty calories a person can choose, why choose this? The novelty?

Because complexity.  But really, do I have to explain BEER and ICE CREAM?

Not separately. But together? Yes, please. Alcohol + Dairy seems like a mistake.

White Russian, eggnog, she-crab soup with sherry...

I can live without those. :)

"When I'm craving vanilla I like Ninkasi Vanilla Oatis with a scoop of vanilla ice cream. This beer is creamy with a very delicate vanilla flavor—when you add vanilla ice cream that creaminess and vanilla is amped up. For days when I want chocolate, nothing beats Southern Tier's Choklat! This beer is like a chocolate bar in a bottle, absolutely amazing! I like a big scoop of vanilla ice cream in this one as well, by doing so you add creaminess and a milk chocolate character to this beer. It's like having two kids, you can't pick a favorite so don't, skip dinner and have two floats!"— Melissa Long-Higgs (Nevada Beverage Company)

These are for me.  Get your own.

LOL.

Mmmmm... real beer floats!  

I just recently got turned on to them at a local beer garten restaurant here in Austin.  So awesome!

Which beer makes the best floats? I was thinking root beer.

Root beer is old school good... but that's only if it's old school root beer.  And it's hard to impossible to get old school root beer anymore (unless you make it yourself) and enjoy a beverage that is a tinge more medicinal and significantly more potent in ingredients (the same thing with real ginger beer vs ginger ale) basis what's commercially available today.  

So for an adult palate seeking the best floats I can say regular beers are, to me, way tastier and silky in combination with ice cream than using today's root beer sodas, unless one is really into really sweet things.  In that case have at it with today's root beers.

If not, I'd guess dark beers with vanilla ice cream complements each other best and, as per above, maybe creamy, lighter beers for chocolate ice cream?  

I don't really know and Geege seems to have much better insight and experience here... I'm just an enthusiastic, johnny-come-lately novice--dang it!  Wish I would have found out this combination earlier... yum!

Now I have to look for an old school root beer recipe.

http://nourishedkitchen.com/homemade-root-beer-recipe/