Friends inconsistencies that are crazy-making

I wouldn't even venture to guess how many times I've rewatched Friends over the course of my life, and I'd probably be horrified if I knew the real number. Suffice to say, I've watched Friends A LOT and I can't help but notice some serious plot holes and inconsistencies.

Now, I'm willing to let some stuff slide (Monica and Rachel's apartment magically changes from 5 to 20 and all of their ages seem to jump all over the place over the course of the show) but there's stuff that makes me genuinely crazy that the writers missed or just ignored entirely.

The one that sticks out the most is Monica introduces Rachel to Chandler in the pilot even though flashback episodes have them meeting MULTIPLE times throughout their college years. I have a hard time believing Rachel would forget the guy at Thanksgiving who lost his little toe. AND they kissed one time at a party!

That's hardly the only major inconsistency in the show (what the hell happens to the chick and the duck?! what about Phoebe's birth mom?!) so I'm curious to know which one bugs you the most. This is all just to say I love the show with all my heart, but come on, writers!