When Gus invites Walt over for dinner, as Walt enters the kitchen there's a small kid's table in the corner covered in toys. As Walt rounds the kitchen island 10 seconds later, the corner is empty and the table and toys have suddenly disappeared.
In the close-up of Saul Goodman's university diploma, the word "privileges" is misspelled as "priveleges".
When Jesse was trying to convince Andrea to buy his meth, he said "I spend so much energy fighting the urge *not* to use" instead of "urge to use".