Peter
Peter would stay awake every night until the other marauders fell asleep. He was afraid that he snored and would disturb them, so he would make sure they were all sleeping before resting. He preferred to ruin his own night, rather than his friends. He would stay up no matter how late the others were. Until he learned Remus' secret, Peter would stay up the whole night every full moon, in case Remus returned in the night. He would set an alarm to be up before James when he started his early morning training.
This was how Peter discovered Wolfstar and Jegulus, as he could hear the others sneaking around. (Obviously he didn't know where James was going, but he was hardly subtle, so Peter could deduce that he was seeing someone).
It wasn't until fifth or sixth year before the others realised and when they did, Peter was very ashamed of it, so it took some coaxing before he was even willing to discuss it with them. Eventually, they convinced him that nothing could make them stop being friends with him, least of all snoring, and he was finally granted a reprieve.
As it turns out, Peter does snore, but none of his friends give a shit.