Hate to drop truth bombs up in this thread, but ladies and gentlemen, referencing the caffeine pill episode in a SBTB discussion is the height of laziness.
I think you discount how few people who don't know SBTB know what the hell that is. But yeah, the oil well episode is far and away the most memorable episode but the Jessie caffeine pill scene is the most memorable scene. Zack realizing Melissa is in a wheelchair at The Max is probably the #2 scene.
Poor oil-drenched Becky... Perhaps the second most tragic animal death behind slater's reptile "Artie."
What do you think came as a bigger shock to Zack: Melissa being in a wheelchair or Laura (from the Christmas episode) being homeless?
Oh man, good call on the Christmas episode. Forgot about homeless Laura.
Guys, how bad were the Indiana years? Major woof. Oh and I know I'm in the minority on this one but I actually think the Tori years had some pretty good eps. 
Good morning Miss Bliss?! Didn't mind the Indiana years. After all, they gave us THE RIGMAS. My sisters and I routinely say "Forever, Trevor," referencing that famous Rigma tagline of "Rigmas. Together. Forever. Trevor." The fact that all those kids and Mr. Belding inexplicably moved to California was one of the stranger continuity issues in TV history.
I thought Tori herself was fine, but aside from the episode where they had to go to prom (?) or something where Tori didn't want to wear a dress (although she did, and it was Blue IIRC), no episodes really stick out with her in them.
And yes, M^2, I enjoyed the Malibu Sands summer. That Staci Karosi (guessing on that spelling) was a ruthless babe.