1. A man, a plan, a canal – Panama!
2. A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal – Panama!
3. Never a foot too far, even.
4. No word, no bond, row on.
5. Some men interpret nine memos.
6. Now Eve, we're here, we've won.
7. Solo gigolos.
8. Senile felines.
9. Rise to vote, Sir.
10. Was it a bar or a bat I saw?
11. Did I draw Della too tall, Edward? I did?
12. A dog! A panic in a pagoda!
13. Step on no pets.
14. "Not New York," Roy went on.
15. A slut nixes sex in Tulsa.
16. Poor Dan is in a droop.
17. Flee to me, remote elf.
18. Not so, Boston.
19. Campus motto: "Bottoms up, Mac!"
20. Eros? Sidney, my end is sore.
21. Lisa Bonet ate no basil.
22. Lonely Tylenol.
23. Naomi, did I moan?
24. Are we not drawn onward, we few, drawn onward to new era?
25. Doc, note: I dissent. A fast never prevents a fatness. I diet on cod!
26. Go hang a salami, I'm a lasagna hog.
27. Taco cat.
28. Test tube butt set.
29. Stressed? No tips? Spit on desserts.
30. No, sir, away! A papaya war is on.
31. In word salad, alas, drown I.
32. Swap God for a janitor; rot in a jar of dog paws.
33. Ma is as selfless as I am.
34. Satan, oscillate my metallic sonatas!
35. Dog food lid = dildo of God.
36. Gabe's on a nosebag.
37. UFO tofu.
Big ups to this list by Ralph Griswold, this one by Neil "Fred" Picciotto, this Quora thread, and this reddit thread — check them out for plenty more.
ALSO read this entirely palindromic poem by Demetri Martin.