My first love out of these two groups was Pink Floyd. I personally prefer a lot of Zeppelin's later work off of Houses of the Holy and Physical Graffiti. Achilles Last Stand is a great song! I like Zeppelin II as well.

I used to love The Wall, but upon further listening I don't know if I like some of the songs as much as I used to. Same with Dark Side of the Moon. My two favorite Pink Floyd songs may still remain Have a Cigar and Welcome to the Machine. However, I also believe that the 1971 release Echoes is underrated and even if it is essentially a Gilmour solo album the one they released in 1987 isn't bad either.

I guess I'm more into Led Zeppelin right now which is why I voted for them. I would contend that they are two entirely different bands with two different styles and bring something different to the table.