Be kind to thy neighbor, destroy all forms of evilness with strict moral choices, resist temptation, protect the innocent, the weak, the brother... And finally, consume yourself as a martyr.
Sincerely, I only felt like a true Paladin in Dragon Age. The dramatic ending reached such levels, that I had myself crying for a virtual avatar created by my thoughts (Christ-Like) and my choices. Dragon Age offered me the best combination to role play as a highly strict figure with sense of righteousness that no other game achieved before. I truly felt the emotion with the possessed child of Redcliffe. In order to carry my faith, I slew the child. The reaction of her Mother was truly touching, however I felt that betraying the Maker by using such arts as blood magic would doom myself. The Pray for the kid's soul to reach the Maker was saddening and beautiful at the same time. Or perhaps the thought of redemption for Loghain, who nearly killed us all in Ostagar (By the way, I gave him the leadership of my party at the final battle). Killing witches like Morrigan & her Mother was truly heroic and just.
At the end, I really felt like I was sitting at the Maker's Side along with Andraste.
In the Icewind Dale series, I nearly had the same enjoyment. IWD offers a background edit, full party customization and several other features which leave you to expand your imagination to fullfill your personal role. However, text choices for a Paladin class were merely present. For example, how would a Paladin-like figure speak with wild spirits, evil outter plane creatures and several other bizarre creations.
Things in Baldur's Gate I & II started pretty well for me. We are given a wide amount of choices, but the personal story of a Bhaal Spawn during the Bhaal Era truly eclipses any sense of righteousness. For example, I always started as a Paladin, however I always finished as a Fallen Paladin. The simplistic ways of good or evil in Dragon Age give you a better condition of being immersed in a role of a paladin, unlike Baldur's Gate, which always forces you through misery, pain & suffering. I highly doubt any Paladin would survive in the Bhaal Era, mainly due to all the deities of Forgotten Realms, almost every single religion feels like a cultish mess.
I understand that we're talking about the madness of a planescape multiverse based upon AD&D lore, this truly twists things in a bizarre manner.
We all know the Obsidian are specialists in terms of choices. If I mentioned previously, that I enjoyed Dragon Age, I could almost say the same from Knights of the Old Republic II. Unlike the first game, where you almost reveal your evilness at the very end of your adventure, KOTOR II offers you a more extent/complex way of choice, giving you a Sith experience at the very beginning of the game. The role of a Sith is nearly unmatched.
And the same could go with New Vegas & Alpha Protocol. We all know that NV is a whole lot better than Fallout 3, and Alpha Protocol surpasses Mass Effect & The Witcher in almost every single aspect.
What I really wanna know, is this:
Are you gonna offer me the possibility to be a highly strict religious figure (Call it Paladin or whatever the hell you wanna call it) ?
Or am I gonna feel like a crazy a baboon chasing **** around a dark tree where nothing seems what it seems ala "Paladin" of Helm. Is it gonna be a simple world, or are good and evil tainted by somekind of multiverse which darkens each others intentions?