So many to choose from really. Olympic #16 and Pebble #14 drive me nuts as it's so easy to fail to make birdie and par always feels like bogie on a par 5 hole.
As far as being a hard hole to par then Merion #5 and #6 and Chambers #7 are high on my list.
DoctorLarry:
Similar problem on BPB #4!!
When the flag is at the front try hitting your second shot to the right of the green. You're left with a punch 64 wedge shot that should get you birdie nearly every time.
If you get the back pin then going for the green in 2 can be worthwhile as you'll probably leave a pitch for your 3rd shot and will have a chance of holing it. Front pin I pretty much never go for the green in 2 though.