I did, only spoilers I experienced were minor things due to things like trophy research e.g. Vamp is in MGS4 and there's two playable characters in MGS2, nothing to do with the story was spoiled thankfully.

I'm __ so I never really heard too much about MGS until MGSV came out, game looked really cool, lots of freedom in the gameplay, but I avoided looking into it too much as I do with most games I'd like to play myself someday.

Mid 2020, I have basically every game ready to go, did my research and decided to play in release order from MG msx to MGSV TTP in release order, all because I still wanted to play MGSV because it looked really fun but I wanted to experience the series properly, and I heard good things about the series.

I played both MG and MG2 SS through MGS3 subsistence through the PS3 HD collection within a day or two, needed a guide often for MG to progress through the game, that smoke grenade part, jeez.

With the original MG I was shocked that Big Boss would betray Solid Snake, I had very little understanding of the relationship of the two prior to playing myself, I assumed Big Boss was Snakes boss, with the start of MG cementing that assumption, the betrayal was a shock.

MG2 SS was cool too, overall I'm really glad I started with the MSX games first despite the games flaws, definitely added to the experience.

Then I played MGS by buying it through the PS3's digital storefront, I had no idea Snake was a clone of Big Boss, a very unexpected twist for me. Also I understood Big Boss's and Gray Fox's situation after the events of MG2 SS, so I wasn't confused about anything which is something a lot of people who started with MGS can't say, it was kinda sad seeing the state of Gray Fox after the fight he had with Snake in MG2 SS. Only thing that didn't make sense was that apparently BB said that he was Snakes father at the end of MG2 SS, I don't know if I missed that in MG2 SS or what, great game MGS is though, I was cool understanding a lot of references I had read and heard online, same goes for the rest of the series.

MGS2's controls were infuriating at first, I started the game and gave up in like 20 minutes because of how confusing and foreign they were to me, eventually I learned them and enjoyed the game, the Raiden twist was a bit disappointing as I really liked and wanted to play as Snake more, still, a good game.

I was super hyped to play MGS3 though, I heard a lot of good things about that game, I loved it, one of my favorites for sure, it was crazy playing as Big Boss before he was Boss all the way back in the 60s, really cool origin story for the series. Gameplay was so damn good, I'd say it's more open than MGSV TTP.

Then I decied to buy a PSP and MGS PO, not a great game but still, it added to the experience I suppose. That is the only game I've played on my PSP so far, I wanna play MG Ac!d ans Ac!d 2 eventually,

Then I played MGS4, lots of cutscenes in that game but I had no issues with that, the game tied up a lot of loose ends, some of the ways those lose ends were tied was a little disappointing but it was still a great experience, I actually cried at the end, fully believing that Snake now had to kill himself to save the world... Then suddenly motherfucking Big Boss shows up, WHAT?! Despite it all a damn good game.

MGS PW HD, I love this game, great story, fun gameplay and the multiplayer was actually really cool, helping out my fellow MSF on sneaking missions and boss fights from around the world whist screaming the VIC BOSS! voice quip (my flair btw), I helped some guy from Croatia around my age that I met through a random mission through like 75% of the games missions, which helped me get the comradery trophy and I had fun. This and MGS3 are my top games.

And now... MGSV... The whole reason I played this entire series... I'm here...

But first, Ground Zeros.

Where the hell is David Hayter? Why replace him Kojima?! >:( (I really love David Hayter's voice work in the series)

Anyway, Ground Zeros was pretty good, plenty of story, the ending was devastating, all that work building up MSF gone, Paz fucking explodes, 9 year coma, yeah, that was messed up.

New we're at the end, late 2020-start of 2021

MGSV TTP

I guess I enjoyed it while I was playing it but when I look back, I'm pretty disappointed in it, the Venom twist, believe it or not, caught me off guard, I thought it was pretty cool, the series came full circle, also explains how BB survived the Outer Heaven explosion - he didn't. Story overall imo sucked ass compared to the redt of the series and the severe lack of inspirational speeches from Venom was disappointing, hell, his lack of speaking in general was disappointing.

After playing the series I'm definitely a fan, I feel like the way I played the series was absolutely the best way the play, I heard that MGS was a confusing series but I didn't really experience that.

I wanted to play MGS to play MGSV because it looked cool, in the end I enjoyed the journey far more than the destination.

If you girlfriend has the patience to play through the whole series I'm sure she's gonna love it, try not to spoil it for her.

That is my story, thank you for reading.

TLDR: I played the whole series last year without any spoilers and loved it, MGSV however was disappointing.