Telly Savalas, hands down. I wanted to like Waltz as Blofeld so much. I always thought he would be the perfect actor to revive Blofeld. Alas, the writing and direction of the story let him and us down.
Stranger coincidence when a Bond story eerily predicted the future:
2004 Everything or Nothing, Bond prevents the city of New Orleans being flooded, the next year Hurricane Katrina floods New Orleans
OR
2015 Spectre, Bond prevents a plot to attack a stadium, Stade-de-France is attacked in Paris
?
P.S.- This isn't meant to be in bad taste. It's on my mind right now and talking about it is the best way I know to cope with it. It's similar to what I did after 9/11, Newtown, Charlie Hebdo (the list is unfortunately endless)