I've had massive frame issues within dense areas of inner Boston and a lot of times indoors. The worst part is when I'm in the Institue the frames drop to the low 30s constantly. I've yet to find any fix for this and it makes gameplay near impossible at times.

Specs are as follows

CPU: i5 3570k 3.4Ghz (Not OC'd)

GPU: GTX 660 2GB

RAM: 8GB DDR3

Bumping this.

Your fix is called a new graphics card or turn down the settings. I'm joking but not really. If you're slowing down in dense locations, there aren't many other conclusions you can make. The recommended graphics card is an GTX 780 3gb, obviously you're below that line.

The more demanding areas and moments will slow you down, it's the nature of a more modern PC game, but not as bad as it could be for this game. Your CPU is below recommended also but that seems to be less desperate, at least for Fallout 4.

Actually, the fix is turning shadow distance down to Medium. This helped my game run an almost perfect 60fps with a i5-3550 and a GTX 980.

Does anyone have any GPU recommendations?

Best you can afford. To be serious, don't base it on this game yet, wait for some optimization to happen.

Which is why I feel it's not my system but the game. It default recommends I run everything at medium and the FPS drops only happen in certain areas. In a lot of spots it'll run a smooth 60. Yet indoors are in certain parts of the city it plummets. It'll even randomly drop in frames and hang if I try to open the save menu.

It is the game check your CPU and GPU usage when the fps drop occurs. Mine actually decrease when the fps drops which speaks of an un-optimized game because in an optimized game the fps would only drop when CPU and GPU are working full power (assuming there are no bottlenecks) and the fps would only drop when they don't have enough power.

I think a lot of it has to do with memory usage, as well. Seems to be a bit of a leak with extended play or around certain areas. I've noticed when my FPS drops, the memory usage shoots up to around 2 to 3 gigs.