For P2P, definitely try Fire Giants. Rune scimitars, dragon med helms, and half keys, plus a few good alchable drops and a decent amount of rune arrows. Also, ankous don't have great singular drops, e.g. dragon items, rune items, etc. but they drop loads of deaths, bloods, adamant arrows, pure essence, and mithril ores. They also drop herbs, and the occasional half key or level 3 clue! If you train Slayer a lot, you can get your combat and Slayer level high enough to kill some really good monsters, that have nearly the best ingame drops (excluding "boss" monsters").