I would have to vote for Gun Nut for my most enjoyable perk. Being able to craft your own weapons just the way you like it - priceless.
Sure you can buy gun mods or take it from other weapons, but I prefer the easy way, to have all the mods I desire right there from the start without looking for them at vendors or other guns. Gun nut worked well with Scrapper cause I needed materials. Also, scrounger for early game was a life saver, when bullets were scarce and money to buy bullets were even scarcer.
Another one I like is sneak, being able to take down enemies without not knowing what hit them - priceless, and not to mention the sneak damage multiplier that makes most enemies a 1-2, sometimes 3 hit kill, at survival difficulty. Rifleman perk adds to that damage just right. Rifles/shotguns that shoot an additional projectile are best in my opinion, double damage to all enemies. Best if suppressed and I can clear out an entire enemy base killing everyone with sneak attacks, without being even scratched in the process. High agility for sneak is welcomed. Not to mention that Sneak level 2 renders enemy's mines, traps and the likes completely useless.
At levels 20-30 Science perk started to shine as I moved from ballistic weapons to energy ones, plasma rifles especially, the perk is like a Gun nut for energy weapons. Energy weapons are way more accurate and have better range. Though I haven't found a plasma gun that fires an additional projectile yet so I'm still sticking to my .50 rifle that fires that second bullet.
As for my vats playstyle, aside from maximizing agility and perception, I've found Action boy lvl 2 good for action point regeneration, Concentrated fire for massive increase in accuracy in vats with each shot to the same body part, then Grim Reaper to get a good chance to instantly restore action points, followed by Critical Banker to have more criticals available, Four Leaf Clover to instantly recharge critical bar, then Better Criticals to more than double the damage with criticals. To get this perks I needed to invest points in luck, witch also helped with the recharge rate of critical bar.
I was more of a glass cannon if rushed by multiple enemies, but since I got the best power armor in the game at level 28 and added some mods to it I could care less if I'm rushed by 10 enemies at once. The X-01 makes Toughness, Refactor or any damage resistant perks look like good jokes.
Now I'm gonna invest in more dps perks and watch those legendaries die in a single round of vats.