Personally, I have mixed feeling about this game. I think I'll do a Pro's and Con's list.
For the pro's.
I love the customization involved: I love how you can mix and match the armor, I like how you can change around the weapons, I like how you can change the colors, and in some cases even put some designs on stuff. I also love how you can customize settlements. I've always wanted to customize the settlements like they let you in this game, so really like that.
It's a big map, and there is a lot to explore: They give you lots of wilderness, lots of city, and lots of town to check out. Lots of abandoned buildings, and lots of underwater and underground. It can take a ridiculous amount of time to explore everywhere, and this is how it should be.
The storyline: I thought this was decent, and I admit, even I was surprised a few times, which IMO, is not something easily done. Also, the use of a character from before the war was an interesting angel not done before.
Relationships with the NPC's: This was a new addition, which I really enjoyed, even though they were more limited then I liked. I also liked how each NPC had there own likes and dislikes, based on their own personal morals and such. I thought it fleshed the NPC's out a bit more then in previous games
Getting to fly in a Vertibird: I can't be the only one who loved this part, even if it was somewhat limited.
There were, however, a few cons for me, and some of them were big ones.
The lack of dialogue and limitations: This was a huge problem for me. While having lots of new voices is great, I would have rather a silent protagonist then have it how they just knee-capped all the options for dialogue. This was probably my biggest problem with the game, and it feels like it gutted much of the depth that could have been given to characters.
The SPECIAL system: I admit, I prefer the old system to this new one. While this one isn't bad, I just like how the system for New Vegas worked better, including the dialogue options that came up depending on your chars reputation/skills/stats. Maybe because it was a little more like the system I grew up with, but either way, I know where I stand.
The lack of choices other then combat: Your character stumbles upon more then a few interesting places. Two of them off the top of my head, are the fighting pit you find Kate in, and the race tracks. Both could have been interesting places, filled with some story and just some general RPG stuff, like actually betting on the fights or races. Instead, as soon as you are seen, everybody tries to kill you. One of Fallout's greatest strengths has always been the ability to solve problems and deal with things from multiple angels. Fallout 3 and Fallout New Vegas in many ways continued with this tradition. The games were more like RPG's, with heavy First Person Shooter influences. Fallout 4 seems to have reversed this trend, making it more into a First Person Shooter, with medium RPG elements.
Minutemen quests/town protection: Preston can go fuck himself. I got so fucking sick and tire of him telling me about a new place that needed something done. I'm the fucking General! How the hell is it I'm the one doing the fetch quests?! And I put twenty chain guns on rooftops, armed my people with Gatling guns, and heavy combat armor specifically so they wouldn't need my help! If you have all of that, and you have a person who has been kidnapped five fucking times by raiders, YOU ARE DOING SOMETHING WRONG!
The DLC content: I will openly admit I haven't played the DLC content for this series yet, because of problems I have to download it here, but from what I've seen, it seems like the DLC material from New Vegas was much better. Each one gave you a whole new area to explore, and expertly weaved into the narrative of the main story. The Fallout 4 DLC, not so much.
Changes to radiation/Survival Mode: I hate how they changed the radiation system. Just don't like it, period. I also think that when they finally got survival mode, they kind'a screwed up as well. While I do like some of it, some of the other elements to it make it much more punishing then it should be. I liked New Vegas's survival mode, but thought it was a little too easy. Sadly, it seems they decided to swing hard in the opposite direction with this one.
I think that about does it for the moment.