I take you think that 4 and Peace Walker are the best entries in the franchise then? Would I be alright just getting those two, or would I need to play some of the others to understand/appreciate things, or even just that there's other ones really worth playing too?
Nah (the phrase as opposed to your name haha) 4 isn;t the best one, but it has pretty tight gameplay and is PS4 exclusive. 3 is on the HD collection, is (chronologically) the first entry and is easily the best. Peace Walker is only really worth playing on console as the PSP version controls awfully and costs more.
Chronologically the games go 3, Portable Ops (side story, can skip), Peace Walker, MGSV, MG, MG2, Metal Gear Solid, Metal Gear Solid 2 and Metal Gear Solid 4.
3, PO, Peace Walker and V all happen in the cold war and follow Big Boss (the antagonist from the original two titles)
MG1 and MG2:Solid Snake (both of these are also on the HD collection) take place in the mid-late 1990s and follow Solid Snake, the clone of Big Boss, and his conflict with his de facto father
MGS follows Snake again, and shifts the focus to various characters and the shady secret society, the Patriots.
MGS2 follows Raiden, with Snake returning as a supporting character throughout the title, and heavily explores the ideas behind mental dopplegangers and double speak
MGS4 follows Snake again, with Raiden providing support this time, and acts as a final chapter to the saga. It addresses themes, characters and plot lines from the three previous blocs of games whilst providing smooth, stellar gameplay (although this one is the game that got the series it's reputation for long cut scenes)