I was talking about this with my girlfriend and it became apparent that there are at least a few variations of "no-intro" songs:
1) no intro - starts immediately in the 1st verse (what I am mostly trying to list)
Here are the first few I could think of:
Big Star - Back Of A Car
Pixies - Alec Eiffel
Shellac - Canada (at least the Terraform version - the live versions ususally get a special intro)

Shellac - Canaveral
Shellac - This Is A Picture (?)
Beatles - I'm Only Sleeping
Beatles - We Can Work It Out
Residents - Lizard Lady
2) no intro - starts with a chorus - I am for some reason much less fascinated by these... most of the examples I though of were pretty bad
Beatles - Paperback Writer (one example that I like OK)
(Also - it becomes arguably vague what is or isn't an intro when it's an instrumental song maybe, or also when the vocalist speaks words over the music moreso than singing in melodies...)
DISCUSS.