The Scion of Legend (CC 110) has a couple potent tricks for a party buffer. Specifically, those that follow Reikhardt get the following three benefits over the course of three levels:
1. 1/day, you may spend some of your own actions to give a similar action to an ally. Yes, you can pass your Standard action to the party spellcaster.
2. 1/day, you can give an ally an additional daily use of an Extraordinary or Supernatural ability that can normally only be used 1/day. There are probably ways to abuse this.
3. 1/day, you can increase the radius of an Extraordinary, Spell-like, or Supernatural ability used by an ally that affects all allies within "a given number of feet" by 50%. There are definitely ways to abuse this, given that it doesn't specify that the effect has to be a good one, or that it affects only allies...
You also get the ability to transfer your Reflex save bonus to an adjacent ally, which is only exceptional since you can give really massive bonuses to an ally's save bonus (you have a Base Reflex Save of +10? Give 'em a +10 bonus to that one save!)
Of the other Paragons, the only other ones that really stand out are Sunyarti (negate a crit, hand someone True Strike, and hand out a reroll on an attack) and Ktolemagne (whose third-level feature lets you take over concentration for an ally).
It's designed for cohorts, and it shows - however, I can see a Scion of Legend (Reikhardt) being used for a bodyguard character in a low-op game. Faithful Companion (the Reflex-save transfer ability) is hilarious if you've got a Action Before Thought - take a massive penalty to your Reflex save, and don't care because you are making a Concentration check instead.