Thomas is my Hometrain

I recently stumbled across the existence of Chuggington, the poor child's version of Thomas the Tank Engine.  I found this quite offensive - Thomas and I go way back.  I read the original books, before it was on television, and Ringo Starr helped them reach the big time.  When I first read the books, Sir Toppam Hat was still known by his pre-P.C. name, The Fat Controller.

Why is it that competition so often seems to come down to twos?  Yes, I know, economies of scale encourage consolidation of production and anti-trust laws prevent unifying the entire market.

There are several types of pairings.  Thomas vs. Chuggington would go in the "Famous Original & Lame Copy" category.  Along with them, Transformers vs. Go-Bots, Lego vs. MegaBloks, iPod vs. Zune.

Other types:

Polite Classic vs. Brash Upstart:

Coke vs. Pepsi, DC vs. Marvel, McDonald's vs. Burger King

Widespread Standard vs. Hip Underdog:

Windows vs. Mac, Android vs. iPhone, Wal-mart vs. Target

No Real Difference, But People Feel Passionate Anyway:

Budweiser vs. Miller, GM vs. Ford