MGS : 9/10 MGS2 : 8/10 MGS3 : 9.25/10 MGS4 : 8.75/10 MGS PW : 8/10 divided by two because it's a handheld game, so 4/10. I'm playing the HD version on the PS3 though but it's still a port of a handheld game. MG: 4/10 MG2: 5/10 MGS GS : 6/10 divided by two so 3/10
MGS - 9/10 - great story, characters, the gameplay holds up well, and the music is flipping awesome. Downside is the key card section. The Twin Snakes - 9/10 - better graphics and first person view. Voice changes for some characters irritate me.
MGS2 - 9.5/10 - Great story with a memorable twist, good characters, great music. The one negative is Rose.
MGS3 - 9.5/10 - Great story, amazing visuals, superb gameplay, fun villans and characters, and just a fun experience. The one negative is that it doesn't run very well on the PS2. 10/10 on PS3
MGS PO - 7.5/10 - Everything about this game is ok, and the plot kind of devalued Big Boss's motives
MGS PW - 8.5/10 - Reestablishes BB's motives, fun gameplay, and good music and voice acting. Suffers from the lack of a second stick but the score is upgraded to a 9/10 with the PS3 port.
MGS4 - 8.5/10 or 10/10 - I'm conflicted here. When I first got it on launch day, I beat it in 2 sittings with a playtime of about 18 hours and then proceded to beat it 13 more times. For nearly 4 years I considered it one of the best games on the PS3. Then the trophy patch came out and I popped it in again just for fun. After playing it, the game just felt good, but not amazing. The characters are cool, the twist at the end is fun if not a little stupid, the humor at times feels misplaced, the gameplay is par, and overall, it's just a good game. But not much else after that revisiting.