It's not difficult to see why Peter loved living with Aunt May, a woman who doted on his every whim and fed him enough Wheatcakes to stop the Juggernaut. Despite first moving out of Aunt May's house during the Stan Lee/John Romita run on Amazing Spider-Man, Peter has returned there time and time again when he's down on his luck, safe in the knowledge that he will always receive a warm welcome and a good feed. But what has May got in return? Only a whole lot of trouble.
There were the numerous occasions where Peter's attempt to hide his secret identity led to health scares for Aunt May, or even left her questioning her own sanity. More troubling was the parade of supervillains that targeted the house due to Peter, including Norman Osborn and Mysterio, with the lowest point coming when Charlie Weiderman burnt Aunt May's house to the ground to get revenge on Peter. Aunt May, we know you love him and all, but next time Peter asks you for a favor, just say no.
When Harry and Peter first met at Empire State University, the relationship between the two was initially rocky. Peter's distracted air made Harry think he was rather conceited, while Peter found out that Harry's father Norman was his greatest enemy, the Green Goblin. Nevertheless, the two became best friends and eventually moved in together. Harry may have had visions of sharing a 'swinging bachelor pad' with his best friend, but this wasn't quite what happened.
In short, Peter was both a terrible friend and roommate to Harry. Rarely on purpose it's true, but the effect was the same. He was rarely there for him and constantly missed out on engagements, with superheroing, Gwen Stacy and University all taking priority over his and Harry's bromance. So distant was Peter that he completely failed to notice Harry's descent into drug addiction and his fragile emotional state. Harry may have blown up their apartment during his Green Goblin induced breakdown, but in truth the boys' future as roommates had been doomed long before.
In a surprising move, the destruction of Harry and Peter's apartment didn't cause Peter to move back to Aunt May's. Instead, he moved in with his old adversary, Eugene 'Flash' Thompson. Because, really, the guy who spent High School stuffing you in lockers and flushing your head down toilets is exactly who you want sleeping in the next room. But to be fair to the more mature Flash, he showed all the signs of being a great roommate, extending the offer of accommodation to Peter in his time of need.
Peter and Flash's time together was short lived, with Peter always looking for something better. He complained that the apartment was too far from the city and was too plain, and then rented the smallest apartment possible as the thought of becoming Flash's roommate permanently was "too heavy a thought to deal with." Geez, Pete. Could you be any more ungrateful?