Oooh I've had some good (well, bad) ones in my tim.
You'll all remember Nasty Bus Driver With an Axe to Grind
Then while at my Christmas job and struggling to reach speed targets "Well, we can't make allowances just because of your sight" Erm, yes you can, and I'm pretty sure you HAVE to... 
Same guy, at same job "You want your keyboard just in the bottom of your peripheral vision so you don't have to keep moving your head to read the screen and type" Erm, I have limited peripheral vision and you knew this...
Again, same idiot (how did I not walk out of that job...?) "How would you feel if you were waiting on a Christmas present to arrive and you didn't get it in time because someone couldn't be bothered to read your writing?" AHEM! It's not a case of I couldn't be bothered, you moron, I actually physically cannot read it without giving myself a headache!
Fortunately, he was just a training mentor, my actual manager was fine and set me a lower speed target, told me to focus on accuracy and was generally easy going because I'd been upfront about my sight.
Countless MN threads saying if you don't drive you're a burden, selfish etc etc. They pop up often enough and I always feel I have to say my piece "I WANT to drive, but read my lips: I. Am. Not. Allowed. Due. To. Disability."
Have had a few "Oh, well you look perfectly normal to me" comments, but that's genuine surprise when I mention the not driving thing (I don't use any aids in terms of mobility - no cane/guide dog, nothing so I do look "normal" as they put it).