Metal Gear Solid 4

[Neon Ignition]

Overall, if I had to pick a fave entry I'd still go for 3 as well. It's a more engrossing game to me and the story owns most of the series.
4 appeals mostly for the ease of fire fights mostly through strafing etc. Even after yet another replay, 2 is a distant last place for me.

[Rep]

Another vote for MGS3, hands down my favourite. The

->Open Spoiler<-

Return to Shadow Moses

part of 4 was possibly the most nostalgic thing I've ever experienced, stunning stuff.