I have used the Whirling Frenzy option for my dwarven Barbarian/Sprit Shaman. At first it seemed too good as a replacement for Rage, but my character's Whirling Frenzy ends two rounds before a regular Rage does because it doesn't increase her CON and my character has had to keep fighting even though she was fatigued, which sucks.
Another player has taken dragon blooline for his samurai, which was appropriate for the DM's campaign because his asian-themed region in his game world is dracocentric.
But what was especially cool was when another DM of mine started his game with all of the PCs being scions of royalty. He has us use the Gestalt rules so that we could go up in Aristocrat and the PC classes of our choice simutaneously. This represented our character's superior training options that would naturally be available to royalty very well, while keeping just just a little more powerful than a regular PC of our level. Because of this, every PC could hold their own in courtly scenarios with their own strong social skills and knowldege skills.
This Gestalt class option would have helped another one of my DMs in the past who had our characters take a level of expert and a PC class for first level, to represent the higher level of education that our characters had. His instructions was to to take all of the good things of having two levels and none of the bad things of having two levels. So we were 1st level for experience point purposes, but 2nd level for hit points and HD to reisist magical effects for example. The Gestalt rules would have worked better for this, I believe.
And for those who haven't read the book, the Gestalt class option is intended for games where there is only one, two, or three players, and all of the PCs use this option beause it does make your character more powerful than an equivelent level regular PC. But by using NPC classes as the other class for a gestalt character, it makes the PC just a little more powerful than a regular PC.
In the past I was contemplating running a thieves' game, where all of the PCs were members of a thieves' guild and had to start off with a level of rogue and then take rogue for their second level before they could take levels in the class of their choice. But the Gestalt option would allow the players to start off in the class of their choice while also having the other class always be rogue levels, and that would work a lot better.
