1.) A couple of days before the release of "EX Unseen Forces" I got a free 2-card sample pack in a Pokemon magazine and pulled a gold star Entei. Normally you'd have to buy around 3 booster boxes of a set to even have a chance at pulling a gold star card.
2.) A 1.st edition gold star Torchic from the Japanese version of "EX Team Rocket Returns". Nowadays finding a sealed pack from this set is probably harder than finding the card itself, funnily enough.
3.) I've never been into collecting the sets that came after the original EX sets (except for the HG/SS sets), but I've occasionally bought a pack or two from a random set just for fun. In this case I bought 3 "Stormfront" packs on sale and managed to pull the SR reprint of base set Charizard. I still have it.
Also, when I was young I was really good at picking packs with good cards in them. I've pulled Arcanine EX from "Legend Maker", Mr. Mime EX from "FireRed & LeafGreen" and Tyranitar EX from "Unseen Forces" out of a single pack.