Has to be BF3 surely and it probably wont be released in 2011 even but still.
None of the others are iconic, doom lost its shine and HL I dont believe most are expecting any release?
Diablo I dont know if thats still followed massively, dont think so. Portal sure maybe
Crysis already disappointed but maybe if it came out again with the whole next generation graphics thing they could just snowball the hype of last time, Ive not seen anything so doesnt rate imo.
Put it this way, which on the list would be bought without a single detail being released. Not thats a clever thing to do, but people will jump the gun and assume - thats the most anticipated name