top 5 right now is tough because I feel like a lot of the top directors don't come out with films on a regular basis...
but I'll go with:
Scorsese
Haneke
Almodovar (his last joint aside)
Bong Joon Ho
Xavier Dolan (only seen two of his but both were on point, he has potential to be great)
honorable mention: Steve McQueen, Lynne Ramsey, Lars Von Trier, Derek Cianfrance, Nicholas Winding Refn, Linklater, Inaritu, Malick
feel like PTA, Tarantino, Wes, and Coens are all falling off a little
I don't know how you can do an all-time 5, it would be tough to do an all-time 50 let alone just 5