I have more than I feel like counting right now, (and I can't compete with some of you nuts ) but some stand-outs are Singapore and Malaysia in my previous passport.

Siingapore has a big blue squre with the words "SMUGGLING OF ILLEGAL DRUGS CARRIES THE DEATH PENALTY"

and in malaysia, I got a visa because I was with a theater group and it says "BEARER IS NOT PERMITTED TO SIT OUR OR DANCE WITH THE AUDIENCE"

Also some great colorful tax stamps pasted in from a bunch of different countries.

I have a minor obsession with walking across borders, so I've gotten out of whatever vehicle I've been in at the time and walked from Costa Rica to Panama, Ceuta (Spanish town on the N.African Coast) to Morocco, Ghana to Ivory Coast and Ivory Coast to Mali. Doesn't work so well in Europe but I love the memories of walking along crazy dilapitated bridges filled with people balancing packages on their heads that looking at the stamps bring back....

Good question, OP....

-remy