Keepers?

[twinsrule]

Would you guys consider the following "Keepers"?
1996 $20
1999 $5
1999 $1
1995 $1
$1 dollar bill K66444439A (because theres 4 fours in a row)
I know some people collect 20th century bills, but even in the 90s?

 

[timbobwey]

for bills in the 90's it all depends on the serial number, I wouldn't just keep one because of those years, not old enough. The bill with four 4's I'd think about keeping for sure.

 

[twinsrule]

How do you tell if the serial number is good or not? I've heard of runs before, but i don't understand them