X is for X-Men vs Justice League and Other Meaningless Preferences #atozchallenge

Day X of the 2013 Blogging from A to Z April challenge. Today's topic: X-Men vs Justice League and Coke vs Pepsi.

Sometimes, based on nothing other than which one you encountered first, you have a strong preference for one group/item over another nearly-identical one.

Given the choice, I prefer

• Pepsi to Coke (except in France, where bottled Coke is delicious).
• Letterman to Leno.
• Justice League to X-Men.
• Burger King to McDonald's.
• Cubs to Sox.

What nearly-identical groups/items do you prefer over another?