HA3: Fuller Is Home Alone
If HA3 were to have Fuller as the main character in Kevin's place, who knows how much better that version were to have turned out? We all know by the mid-to-late 90's, Macaulay Culkin was on hiatus, while his brothers Kieran and Rory were nice enough to stick around.
So if HA1 came out in 1990 and HA2 came out in 1992, HA3 with Fuller as the lead character would've come out in 1994.
But alas, that wasn't meant to be. I had written my own fanfic about Fuller being home alone, but I no longer have it.