Currently, following their PnP source, Rangers can get up to 5 Favored Enemies at level 20, and you can choose any monster type, from a list composed of over 20 choices. It is well-known that many items on this list are under-represented in monster population (Plants), while others are almost universal (Undead). The major problem is that in heroic content, FE damage is supposed to be a major feature for rangers, giving up to +13 damage against their favored enemies (+17 if you get DWS T5 and Primal Avatar), but the list is so vast that you end up doing the same list as everyone else (Undead, Giant, Evil Outsider), and complement the blank spaces with your current farming objectives (Dragon, Elf, Human, etc), or crit-immune mobs for the extra damage (Elemental, Construct), and thus, over half the list is never even considered upon. I mean, when was the last time someone picked FE: Halfling or Ooze?
My proposition is to merge some categories and making them more accessible to all levels content (eg, you don't need FE: Dragon until you start running at least Tor). I was thinking on the following categories:
Untouched: Undead, Giant, Monstrous Humanoid, Construct, Aberration. Those already encompass a good amount of mob variety and frequency.
Elemental: Mephits get added to this list, since currently no FE encompass them. Otherwise, untouched.
Outsiders: Not alignment-based. You can damage devils, tieflings and archons with the same efficiency.
Player Races: Merge together Human, Elf, Halfling, and Dwarf. Warforgeds are on Construct, while half-orcs are considered orcs.
Savage Species: Merge together Goblinoid, Orc, Fey and Gnoll.
Reptilian Creatures: Merge together Reptilian (Kobolds, Troglodytes, Lizardfolk) and Dragon.
Natural Beasts: Merge together Plant, Ooze, Animal, Vermin, and Magical Beast
This would reduce the list to 11 options, which you get to choose half of them (5 choices, plus choice of going DWS T5 or not). And while the big 3 might still be tempting, given the sheer numbers of mobs the merged categories, you might consider them.
Feedback?