The first thing to figure out is that I very rarely care about lyrics. I like singing, but lyrics are generally "meh" for me. The salsa bit in Fool in the Rain sounds cool because it's Zep and you don't expect to hear salsa from a rock band, but as salsa goes...it's kinda pedestrian.
I actually like stuff with a driving rhythm as long as it's not driving a freaking Yugo, which is how both Fool in the Rain and D'yer Mak'er sounds to me. To me, it sounds plodding, not driving.
Love Kashmir. Love the addition of the strings, but part of the trick to Kashmir is that while Bonham is drumming in 4/4, the strings are playing in 3/4, which means you've got 12 beats before they match up. That makes the song sound more intricate, flowing, and complex than many other rock songs. I still think it's a few minutes too long, though, and I do like some longer songs. But there's not really much in the way of transitions, etc.. in it. So it's kind of 9 minutes of the same stuff.
I like When the Levee Breaks. It's a very good old country/blues song, but what Zep did that made it a bit more unique is some gaming with the recording speeds, which is why they rarely played it live. The harmonica over the top makes it more interesting too. But honestly, I do get bored after about 4 minutes or so into the song.
Another "driving rhythm" song is Whole Lotta Love, which is one of my absolute favorite Zeppelin tunes.
Don't like reggae at all, so D'yer Mak'er is kind of a non-starter with me as Zeppelin's (rather weak, IMHO) attempt at reggae. I actually dislike that song rather intensely.