Best Favoured enemy types?

[Skellimancer]

Worried what to pick! Any suggestions?

[MalkavianX]

Undead, evil outsiders and giants is what I usually start with. Might change one or two out at later levels though.

[Fleckislaupir]

My usual choices in order:

• Undead: constant menace from lvls 1 thru 15 or so (Necro IV); not much in the high teens, but they show up again in epics / Eveningstar. And since they're SA/crit-immune, all the extra dmg helps.
• Giants: also includes trolls & ogres, so it's a great pick for leveling thru Gianthold; and now that GH is epic-fied, it's become that more useful at endgame.
• Evil Outsiders: mostly for Vale & Amrath; also useful for Threnal, but I've usually outleveled it before I have EO FE.
• Aberrations: grab bag of different monsters - beholders, scorrow, mind flayers, etc.
• Constructs: mostly for House Cannith quests (LoB etc.).
• Elf: mostly for drow in MotU.

[~Furiyen]

My usual choices in order:

• Undead: constant menace from lvls 1 thru 15 or so (Necro IV); not much in the high teens, but they show up again in epics / Eveningstar. And since they're SA/crit-immune, all the extra dmg helps.
• Giants: also includes trolls & ogres, so it's a great pick for leveling thru Gianthold; and now that GH is epic-fied, it's become that more useful at endgame.
• Evil Outsiders: mostly for Vale & Amrath; also useful for Threnal, but I've usually outleveled it before I have EO FE.
• Aberrations: grab bag of different monsters - beholders, scorrow, mind flayers, etc.
• Constructs: mostly for House Cannith quests (LoB etc.).
• Elf: mostly for drow in MotU.

Pretty much this list, but as I tend to play 12/14 Ranger splits I generally go Undead/Elf/Evil Outsiders upto CitW then swap Elf for Giants for Epic GH.

Some Small Notes:
1. Aberrations also includes Lolth, funnily enough.
2. There's a lot of undead in the Demonweb/CitW so FE: Undead is still nice for chopping through stuff towards end game. The Truthful One is a Dracolich, and thus Undead as well.
3. If you have a 4th or 5th FE, Constructs and Elementals are always fun choices. Constructs includes Shroud Portals.
4. Primal Avatar can give you a bonus FE choice, and thus another stacking +2 FE Damage.