Thermal paste is thermal paste really. Arctic Silver is what I usually use but as long as you're not using like toothpaste or really really low quality stuff you're only going to be talking about a 1-3 degrees difference at the most. You're better served tweaking voltages or throwing an extra fan for how much impact it would have. Yes the higher dollar stuff will do a slightly better job, but I would just get what you're familiar with.
That said, Arctic Silver really doesn't age in my experience. It might settle a bit so squeeze out the first bit on a paper towel but I've reused the same tube several times over a few years with zero problems.
That said, Arctic Silver really doesn't age in my experience. It might settle a bit so squeeze out the first bit on a paper towel but I've reused the same tube several times over a few years with zero problems.