Supermutants are easy unless they have that helmet on. The ones without helmets = dead with 4 VATS shots to the head with my laser pistol.
The ‘vampire’ thing is interesting because
they aren’t really vampires… They are simply cannibals who have figure out that they don’t have to eat flesh to satisfy their hunger.
I think it fits the post apocalyptic scenario quite well.
Had a fun quest with the Brotherhood of Steele that was halted early due to a supermutant making the quest givers head explode 
.
The second chapter of that book the girl is trying to write has one quest
where you put a sensor in an egg… Yeah.. that was HARD because I did it without killing any of the crab people x_X.