I put my bag in once parallel to the aisle because it doesn't it didn't fit in the last few planes I was on but then someone moved my bag and it actually did fit. I felt bad but I boarded late so I didn't want to hold people up by fiddling around with my bag. I guess I'll try wheels in first and then move it the other way if it won't fit.

Also, are First and Business Class bins bigger than those in Coach?