My approach to this varies with what kind of method I am using at the time. If I am using a method with a lot of emphasis on percieved intensity, and pushing very hard (think 5/3/1 type of routine) I prefer to ramp the sets to one all out top set where I give it my all. I think this works especially well for building muscle via the big lifts.
However, I think that for pure strength gain, straight sets are a better option for some lifters, myself included. I believe it gives you more attempts at setting up for the lifts. In addition, I believe that with a moderately heavy weight, you can still get stronger, but keep your technique tight so you don't get into bad habits. For this type of training, I think the name of the game is moderation; using manageable weights with decent volume to spur adaptation.