InVinoVeritas said:
So, what, in your opinion, is the optimal rank amount for various skills? Which do you max out? Which do you rise to some level (5 ranks?) then forget?
IMC, Knowledge skills can never be too high. That includes Spellcraft, at least the way we use it.
The "perception" skills -- Listen, Sense Motive, Spot -- can't be high enough either...depending on how your DM plays. In most games, surprise is determined by one of these skills. Usually that's Spot, but in well-crafted games it could be any of the three. Its best if at least 2 PCs in a group can max out these skills, just in case.
Skills like Balance, Climb, Jump, and Swim are good "
5 ranks and then out" skills. Those 5 ranks will cover all of the common situations. And if the DM is being nasty with high DCs in these skill checks, there's no way to have enough ranks in them anyway, so why bother with more? Synergy from Balance and Jump are nice for that all important Tumble skill.
For those likely to get into melee, Tumble is a must. Max it out. Not only does it prevent AoOs from moving, but it helps with standing from prone. Once you're at a +25 check, you can stop.
For spell-casters, Concentration is a must. Max it out, at least until a +30 check.
For the face-man, Bluff and Diplomacy should be maxed. Gotta love turning people into fanatic followers!
For sneaky types, there's all the rest of the skills. I'm not sure I've seen a high enough Search or Disable Device check.

The rest of these sneaky skills (Appraise, Disguise, Hide, Move Silently, Open Locks, Slight of Hand, etc) are *really* DM-dependent
and Party-dependent, so there's really no way to generalize how many ranks to put into 'em. For example: if the DM gets all happy with scent or blindsight or tremorsence -- or if the rest of your party pretty much always kicks down the door and rushes in -- there's little point to the Hide skill.
Most pointless skill? Heal, I'd argue. With a Cleric around, why bother? 0 ranks, baby.