Seriously, one of the major things I (we) hate about buying sweaters is that they are all WAY too large. A sweater in my opinion should be about 2-4" larger around the chest than the actual chest measurement. I am a 40 chest, should properly wear a size medium, and usually a small is closer to my size and sometimes still too big. I prefer my sweaters to fit close so they can fit under whatever else I wear, such as a close fitting jacket.
I should also mention that the sleeves should be proportionally tighter on most sweaters as well. I don't have skinny arms, but I don't want a whole bunch of extra fabric around them either. I like them to fit inside a coat or jacket without bunching up or binding, and I find the fitted look much more pleasing as well.