I usually cash out a few thousand in $50 to look through right after pay day, then deposit them to pay bills.
Here is my list of some recent $50 notes with "interesting serial number". They all have some folds/crease line though. I am pretty sure most of them are not worth keeping so just want to have some confirmation:
Series 2001:
CA 01201522 A (four numbers serial)
CD 07097277 A (four numbers serial)
Series 2004:
EL 00079769 A (four numbers serial) - only if the 6 is a 9
Series 2006:
IB 33008599 A (five numbers serial)
IL 35473447 A (four numbers serial) - only if the 5 is a 4
ID 44122284 A (four numbers serial)
IB 10066005 B (four numbers serial) - this may not worth much but it look appealing to me.
IF 25215254 A (four numbers serial) - only if the 4 is a 1
IF 19896689 A (four numbers serial)
Series 2009:
JD 01014442 A (four numbers serial)- only if the 2 is a 4
JD 01141604 A (four numbers serial)
I usually try to save at least one or two best $50 notes each month then go over them after a few month to pick out a few best to put into or upgrade my existing type set (one per denomination - series); I cash the rest of them in, either to pay bills or use the sum to purchase some coins (like a short term saving account). Some of the one I keep kinda act like a small rainy day account for emergency funding.... if ever needed.