So, funny story. I did a quick search for something to cite to verify my claim that House is based on Sherlock Holmes. I started—as you do—with Wikipedia, figuring that I'd trace the references there to something more dependable.
It turns out that Wikipedia cites me. Or, more specifically, an article I wrote about a million years ago for FactCheck.org. I figure that means I don't have to cite anyone on this topic. If you want to save time, you can just assume that I'm right and go back to the main article.
Still here? Fine. Here's some evidence.
Both are famed for their ability to draw conclusions by observing details that most others miss.
House's address is 221B.
The pilot episode features a patient with the surname "Adler."
In the season 2 finale, House is nearly killed by a patient named Moriarty.
Both men struggle with substance abuse disorder—particularly when in between interesting cases.
Both are accomplished musicians—Holmes plays the violin, while House prefers the piano.
Perhaps my favorite in-show Sherlock Holmes reference takes place in the season 5 episode "Joy to the World". There Dr. Watson Wilson has presented House with a rare first edition of A Manual of the Operations of Surgery by Dr. Joseph Bell.
Bell was a (real) Scottish physician who practiced in the late Victorian era. And Bell was himself famous for his inductive reasoning—specifically, his ability to draw conclusions about things like people's hometown, current residence and profession by observing details such as accents, the color of mud on their boots and their calluses. On several occasions, Bell deployed his reasoning skills to assist in police investigations, becoming one of the early pioneers of forensic science.
Bell's ability impressed his medical students, including one who would later abandon medicine in favor of a writing career.
Sir Arthur Conan Doyle would mail copies of each Holmes story to Bell, the mentor whose abilities he transferred to his most famous literary creation.
The creators of House completed the circle, returning Holmes to the profession of inspiration, while also providing a delightful Easter egg for fans.