Classes with big frontloaded skill bonuses

[Zaq]

What classes can you think of that give you a big (ideally, I'm thinking at least +4, but this is all just theoretical anyway) bonus to one or more skills for only a level (maybe two) in the class? The skill bonuses should be either constant or at-will. (This isn't for a character who's ever going to see the light of day—I'm just considering what's out there.)

I got thinking about this by considering the Warlock and the DFA, both of which have invocations that give +6 to certain skill checks. Two levels of Warlock can get you, say, Beguiling Influence and Leaps and Bounds (or Otherworldly Whispers or All-Seeing Eyes), and a level of DFA will get you Draconic Knowledge. Then we have the Marshal, which gives +CHA to X-based skills for a one-level dip, where X is your favorite stat. One level will get you one stat, or three levels will get you two stats.

Then there's the Ardent. The Knowledge mantle's granted power gives you a +5 on any Knowledge check when you expend your focus. This isn't a constant bonus, but at least it's at-will.

The Incarnate and the Totemist get very little other than skill bonuses at low levels, but the skill bonuses they get are pretty decent, especially if you have a point of essentia from your race or something. You can pick a couple key soulmelds and get a consistent +4 or +6 from them.

After that, though, I'm not sure where else to look. A Changeling with Racial Emulation can spend five levels as a Wizard to get a floating +6, using the Elf Generalist 3rd level ability to double the typical +3 from a familiar and the Changeling Wizard 5th level ability to change their familiar at-will, but that's a lot of investment compared to the one-and-done you can get from the rest of the things I mentioned.

There are probably some PrCs that are worth looking into. Exemplar gives you a +4 on a skill of your choice when you take your first level. Blade Dancer is a pain in the butt to enter, but it nets you a whopping +10 on Balance/Jump/Tumble as its first level.

Of course, I have to mention the Truenamer, which can give you a +5 on ALL skill checks if you can reliably use Universal Aptitude on yourself. That's far from a trivial investment, though.

If we're counting the Ardent, we might as well mention a few psionic feats that let you expend your focus for a nice skill bonus, specifically Inquisitor and Mental Leap. Those aren't constant, and they're feats instead of classes, though of course we can get them with a dip in Psion or Psychic Warrior, as either of those classes will give us a bonus psionic feat at first level.

What else is out there? I like the idea of a highly unconventional skill monkey who has unnaturally high skill checks from a whole bunch of disjoint sources. I feel like there's got to be more out there. So help me out, Playground. What other classes (base or prestige) give you nice meaty skill bonuses as soon as you enter them?

[Bakkan]

Factotum gives Int to Str- and Dex-based checks.

[Thurbane]

A 1 level dip in Marshal lets you add your Cha bonus to you and your allies skills and checks related to one ability score (i.e. Str, Dex, Con, Int, Wis, Cha). Dex is popular because it adds to Initiative rolls.

Not a class dip, but Illumian gets to pick two power sigils, that can relate to any ability (similar to Marshal, but for the Illumian only), that give +1 to all related skill (and ability) checks; increasing to +2 at 2nd level. There is a feat that increases it to +3.

[dextercorvia]

The Stealth Focus of Chameleon gets you +2 to a bunch of skills.

Binder: Binding Naberius lets you take 10 on Bluff/Diplomacy (which is a de facto bonus) even in stressful situations, and rush without penalty. It also allows you to use several skills untrained, which might be handy for something with more bonuses than SP.

Master of Masks gets several skill bonuses depending on the mask -- +2 at 1st level, +4 at 3rd level, and +6 at 4th level. It goes higher from there, bu that is the frontloaded part.

[Vhaidara]

Binder: Binding Naberius lets you take 10 on Bluff/Diplomacy (which is a de facto bonus) even in stressful situations, and rush without penalty. It also allows you to use several skills untrained, which might be handy for something with more bonuses than SP.

This. Binder with Naberius is like a +20. I have a second level character (Warlock/Binder) who takes 10 and diplomances a 29. Considering a dip into marshal for another +7 so that at level 3 I take 37, enough to bring hostile to friendly as a standard.

[A_S]

One of the SRD Diviner variant class features gives your Int bonus to any skill check 1/day (at first level).

Cloud Anchorite 1 gives Wis to Balance, Climb, and Jump.

The Halfling domain (so Cleric 1 or similar) gives Cha to Climb, Jump, Hide, and Move Silently.

Guidance of the Avatar probably deserves a mention; you can get it with either Cleric 3 or Cleric 1 and a wand (or just UMD and a wand).

Bard 3 gets Inspire Competence. There might be ways to improve this check beyond the basic +2? Not sure, people don't write a lot of handbooks on optimizing Inspire Competence.

[dextercorvia]

If we take casting dips into account, Wiz/Sorcerer/Magewright gets Magecraft as a 1st level spell. That is a +5 on any craft check. Probably not worth the dip just for that, when it can be had so cheaply on a wand.

[nedz]

Changeling Rogue ACF (RE, p 121): Add one knowledge skill to class list, 10 skills per level
I think that this only applies at levels 1, 3 and 8

[Sian]

Blade Dancers (OA) first level gives +10(!) to Balance, Jump and Tumble Checks, and lets you take 10 on those three checks

[Socratov]

Warlock has the least invocations that give great bonuses (at will 24 hour buffs):

Beguiling Influence: +6 to Diplomacy, Intimidate and bluff
Leaps and Bounds: +6 to balance, Jump and Tumble
All Seeing Eyes: +6 to Spot and Search +free Comprehend Languages
Otherworldly Whispers: +6 to Knowledge(Arcana), Knowledge(Religion) and Knowledge(The Planes)

Any one of them can be yours for a Warlock 1 dip.

Also, if you are looking for a lvl 6 diplomancer, I present you Blarney Stinson