The search box in Wikipedia suggests auto-completion when you start typing. For example, if you type “je” in the English Wikipedia search box, you’ll get the suggestions “Jews”, “Jewish”, “Jerusalem”, “Jesus”. (Jews kick ass!)
If you search for “differences between”, you’ll get this list:
The top spot belongs to “Differences between editions of Dungeons & Dragons” and that shouldn’t be surprising: the article “List of Advanced Dungeons & Dragons 2nd edition monsters” only recently lost its first place in the list of the longest English Wikipedia articles by number of bytes to “2011 ITF Men’s Circuit” (it’s something in tennis).
Out of ten suggestions, six are related to languages. American and British English are considered one language, but everybody admits that it has many variations by pronunciation, spelling, vocabulary and many other parameters, and lots of people love to bicker about the spelling of “meter” and “aluminum”. Bosnian, Croatian and Serbian are one language that has different names for reasons that are more political than linguistic. Something similar can probably be said about Malaysian and Indonesian, Norwegian Bokmål and Standard Danish and Scottish Gaelic and Irish, but i know very little about these pairs.
Spanish and Portuguese are related, but definitely separate and mostly mutually unintelligible languages. It’s been said that it is easier for Portuguese speakers to understand Spanish speakers than the other way around, which is interesting, but it doesn’t really justify an encyclopedic article, as in the other cases. In fact, i am somewhat surprised that “Differences between Brazilian and European Portuguese dialects” is not in the list, given the huge number of arguments about it in the Portuguese – sorry, Lusophone – Wikipedia.
“Butterflies and moths” is probably the most serious article in this list, but that’s probably because i’m not a Biologist.
And the last two articles are about movies (James Bond – movies vs. novels) and religion (Codex Sinaiticus vs. Vaticanus), which is also very Wikipedia, the encyclopedia about which someone said that it has more stamp collectors than good writers. (Citation needed; I can’t find the original quote.)