Simple, but true.

For me personally: VC since I'll be playing that to death the coming weeks.

I don't really care about any old games getting trophies now that GTA IV has trophies

MGS4, Ratchet, Oblivion, and maybe CoD4.

Of those, only MGS4 has the slightest chance of getting trophies...

MGS4, and MGO should have sepperate trophies, and Valkyria Chronicles.

Fifa 09 is receiving DLC in March called ULTIMATE TEAM. An awesome new mode. The PS3 is also getting trophies when the DLC arrives.
The DLC will also have extra trophies / achievements for this mode.

All of them obviously but my top 3 would be

1) Metal Gear Solid 4
2) Oblivion
3) Rock Band 1

Devil may cry 4
Metal gear solid 4
Call of duty 4

MGS4

Tomb Raider: Underworld
A patch was announced on February 12th but has not been released until today. How can something like that take longer than two and a half month?!?

Ratchet & Clank: Tools of Destruction
The trophies could have been linked very easily to the ingame reward system.