I have MGS 5 still to play so can't comment but FO4 is not GOTY material. The main quest is OK but the rest of it is pretty dull, just endless places to waste time looking for a magazine that gives you a tattoo. 90% of my time in this game feels like a waste of time, I'm just rushing through the story now to get it done so I can move on. Base building is the worst bit of it, given up on that altogether. MGS 5 is next on my list, I don't expect it to be GOTY either, that was easily Witcher 3. Also monkey you're opinion on the series being over rated is invalid. Like me you've only played 1 and 2, enjoyed 1 but didn't enjoy 2. We are both in the same boat there but as neither of us played 3, 4 or 5 can't really give an opinion on the series overall as haven't played over half of it.
I loved FO4 but I can see why it wouldn't be GOTY for most people. FO3 and New Vegas also excellent but not GOTY material. The Witcher 3, love it or not, is GOTY material.
The order of metal gear goes from MGS3, portable ops, peacewalker, ground zeroes, phantom pain, MG1, MG2, MGS, MGS2, MGS4. That's nearly 30 years of (mostly) consistent storyline. That's an incredible achievement in itself. The series is always reinventing itself, improving its gameplay and delivers a crazy but good plot and isn't afraid to have fun. The series has invented a lot of videogame staples. The amount of detail and Easter eggs in the games (not including phantom pain) is fantastic. Very few developers manage this level of detail and quality and polish for their games. It's well worth playing mgs3 before ground zeroes/phantom pain
I was skeptical of Fallout 4 myself, but have found it to be a lot more fun than FO3. I haven't even bothered with the main quest so far. It doesn't really break any new ground in terms of item collecting or leveling, but I think the environment is significantly more interesting than FO3.