Best: Jury Rig, Hand Loader, Shotgun Surgeon, Cowboy, Comprehension
Worst: Here and Now, Swift Learner, anything VATS related
NOTE: Swift Learner is not that bad (2 or 3 ranks) when you are constantly gaining XP from Speech challenges. Instead of gaining 50 XP, you gain 65 XP, it builds up. If you don't do Speech, then yeah, SL is stupid.
There is so much to do out there you can easily make Level 30 before you set foot on the strip for the first time....why waste perk slots on something that become worthless once you reach the level cap? I use Speech all the time and I don't take Swift Learner at all...I use the slots on things that give me new abilities or benefits...usually to kill more efficiently...right up to the end instead. IMO it's only useful to people with no patience that have to level up ASAP to be happy. More power to 'em but I won't be joining them.
I find the very simple and amazingly cheap 'weapon repair kit' trumps the jury rigging perk. Easy and very cheap to buy parts, easily scavenged too, for it and 50 repair. I only fix armor at the repair guys.
I find Jury Rig so spectacularly useful in so many ways I'm surprised the usual suspects aren't composing thread after thread demanding it be taken away or nerfed...it's even better than the Vending Machine, whose normal function some call a "exploit".
To me, Jury Rig helps makes NV a more spiritual experience. To those without Jury Rig and Survival skill, the Mojave is a harsh wasteland where the means of survival are only present in isolated pockets of civilization. To those of us with them, it's a tough but loving mother who provides her children with her endless bounty. Where some see a empty and desolate wilderness, we see a place that teems with life that can easily provide the Mojave's Apex Predator...the Courier....with everything he/she needs to thrive. Every creature has it's place....from Geckos who nourish out bodies and provide hides that can be sold for caps to Vipers, Powder Gangers, Fiends and Freeside thugs who provide
clothing Outfit Repair Kits,
armor Armor Repair Kits, and
weapons Weapon Repair Kits, along with other useful things like chems or sometimes better weapons that enable the Courier to harvest prey more efficiently. They can even serve as food for those inclined that way. If the mojave's bounty is in excess of one's need...and it often is...that can be taken to vendors and sold to buy the few items the Mojave cannot provide herself.