As usual for me, I'm behind several years on the games I play. So I've just finished playing Fallout 4. Well, "finished" in the sense that I've hit the limit of what I can stand doing, not that I've run out of things/quests to do. I did finish the main quest though. So here are a few thoughts about it.
I loved the crafting system for weapons. It was a nice touch, making all that junk that's lying around in every Fallout game (at least 3 & NV that I've played) actually useful, and scrounging has the post-apocalyptic feel. It also was useful, letting you make much better weapons out of the ones you find. I love crafting too, which helped :) Some of the options were really good too, changing how the guns felt shooting or letting you tailor your weapons to your playstyle, like close and automatic or long-ranged sniping. The plasma option to turn your gun into a mini-flamethrower was a totally great addition (so much fun). On the downside, you do have the omnipresent level grind where you go from 'standard receiver' to 'advanced receiver' to 'amazingly godlike receiver' for your base damage upgrading. I've never been fond of that style of mechanic, though I guess it is unavoidable with a level-based game.
Likewise I loved the settlement building. Had that perfect feel for trying to create a new, better future. Again, loving crafting helped. It was awesome to build my own mansion, using large glass windows to look out on the ruined city (from my island, after ridding it of Milelurks). But that charm really wore off when I realized there was no good reason at all to actually build a settlement. All it gave you was some crafting stations, which are everywhere, a place to store your junk (that is you didn't like crafting wasn't an issue), and a few useful crops (glue is used in everything, literally, so being able to grow your own was a huge plus). Overall though, they can get attacked, side-tracking you from you were doing to help. Settlers do not level up, and have no gear really, so equipping them to survive the higher level enemies was a micromanaging pain the behind. They take a lot of resources to build, and just again, you get little from the sense of accomplishment from them - which isn't something to scoff at, but wears out fairly quickly.
Like the last 2 Fallout games, the main quest is something you can really ignore. I didn't care at all about finding my son, and waited several days of playing before working on it. The faction quests were okay, though I mostly focused on The Brotherhood of Steel myself. The ending was not really very satisfying - but that's been true of the last 2 Fallout games in spades; I HATED New Vegas for making me walk off into the sunset when I'd worked so hard to make my own robot army to take over the place.
Otherwise there's plenty to do, and some fun quests (the robots on the ship was awesome, the witchcraft museum was great - even knowing the plot really, and the haunted mine was totally cool). I did not like any of the companions, until I got the Automatron DLC and loved Ada your robot friend. The difficulty was good for me, not too hard, though near the end it did start to get pretty easy. Getting your first suit of power armor early on was fantastic, though the fight for it was pretty intense.
I liked the game. For the discounted price I got it from GameStop it was well worth it, and I thought the DLC was decently priced for what you got.