I'm a huge Doors fan, a few facts to clear things up:
For the most part Doors songs are credited to "The Doors" as an entire entity. This was something Jim Morrison brought up to the band before they were signed and they all agreed on it since they felt that everyone made a significant contribution.
The only exception is on the album Soft Parade where Jim wanted the credits split up because he did not want people to think he wrote certain lyrics. One strong example is the track "Tell All The People". Jim had a huge problem with the line, "Can't you see me growing get your guns." He really didn't like the part about the getting the guns.
That being said, Robbie wrote almost all of Light My Fire (except for a few lyrics), Love Me Two Times, Love Her Madly, Touch Me. That's some of their biggest hits.
But I agree that Ray was really the glue that held the band together, playing keyboard bass and various keyboards, he filled up a lot of The Doors' unique sound.
Did anyone read the biography of Danny Sugarman, manager for The Doors during the 70's? As manager, he got a full member split and he referred to millions he was raking in on an annual basis. This was in the 70's, well before at least two huge Doors resurgences in the 80's and 90's (and that's not including the movie, a few new Greatest Hits packages, etc etc etc). Also, I have an old Keyboard Magazine interview from circa 87 where Ray basically said he was doing more than very well. I doubt they're hurting for cash.
One last thing: doorknocker, I completely disagree with your statement that the Doors only had one good album. EVERY single album with the exception of Soft Parade was strong and considered in the top albums of all time. Even if you're just a casual fan, the first two albums, The Doors and Strange Days are in the top echelons of the greatest albums of all time.