Take a look at the new SNS Anacyclus XT... that's been one of the most common natty appetite increasing supps for quite some time (dating back to the OG anabeta, etc). For me, I also seem to get very hungry simply from additional stimulation of my gut (i.e. adding a small protein shake here and there through the day). I fast because I have to keep that under control or ill balloon up ha.
weed for sure will make you hungrier as well... if you're just looking for pure weight gain, as mentioned above, the way to go is def calorically dense foods like oils, nuts/butters, fatty meats, etc... higher fat and sugar will add cals quickly with minimal volume. Add a shot of oil to any shakes and such for easy cals.