@d123 That's something I didn't really think about. I might be overthinking it but it seems like it should be symmetric. So the opposite situation could happen where something else on the board dumps a lot of current into the ground thus raising the ground voltage in the vicinity. It seems like in this case you would want the cap closer to the ground pins. I'm not disagreeing, more just thinking out loud. I do generally put the bypass caps near the Vcc pin, I was just working on a layout where there was very little room near the Vcc pin but a lot of room near the ground pin. It sounds like it's mostly ok to do either.
@KlausST Ok, I do try to put it near the Vcc pin but mainly out of habit/convention. But I had to put one near the ground pin instead which got me thinking about this. When you say a 'good ground plane', what makes a ground/Vcc plane good? Is it just having a very solid ground plane without very narrow connections and also being a relatively large?