It's been said before, the last time we had an essential psych thread, but don't sleep on Hard Ride by the 1910 Fruitgum Company. They were known as a bubblegum band, but this LP (their last) was a conscious effort to go all-out psych, and it worked. Maybe two of these songs are straight-ahead pop ("Don't Have To Run & Hide" and "The Train"); the rest is pretty much what you're looking for. They almost got booked into the Fillmore East on the strength of this album, until the producers told the bookers who it was.
I'd also keep an eye out for Portraits by the Buckinghams. Like the Fruitgums, they were also known for poppish AM radio singles, but if you remove "Susan" and "Hey Baby, They're Playing Our Song," the rest of it is pretty experimental. By ANYBODY'S standards.
I'm recommending these two in particular because they're usually cheap. (And if you ever run across the Buckinghams' Made In Chicago compilation, know that sides three and four are the entire Portraits album.)
Edit: Mandrake Memorial and Puzzle by the Mandrake Memorial are on key...we were just mentioning them in the Poppy Records thread. Clear Light's album on Elektra (reissued on Sundazed) is a goodie as well.