I intend to buy a PSP before it dies away and get all these games on the cheap. Thanks for the list but I would add Persona 3 too.

isn't 
Mana Khemia: Alchemists of Al-Revis
 
the ps2 game? The Mana Khemia game on psp got absolutely trashed by critics - something like a 41% metacritic rating. The ps2 games did well though

Fantastic post!
 
I have finished Crisis Core and Valkyrie Profile 2, and now I will commence my search for the others that you mention. 
 
I agree that the PSP generally cops a bad rep regarding its games, but I truly believe it is an awesome platform. There are a whole heap of decent and excellent games on PSP...

I totally agree the PSP has a solid JRPG library, which is nice considering I do my JRPG playing on handhelds exclusively now.

Persona 3 Portable is another solid game. I never finished FES because of AI, so P3P was just what I wanted. The Female MC was also a great addition.

Monster Hunter Freedom 3 this year!

Hmmm... Looks like I actually might enjoy Crisis Core. Question: is it a bit lighter on the story? While I can appreciate a good story, I prefer it to be well told, and I have felt that nearly every Final Fantasy game has been way to heavy handed with it's story and packing way too much exposition at a time I just want to play.  
 
Also:   Mana Khemia sounds fucking perfect for me.

Wow, what a relevant, interesting, thoughtful post. 

Crisis Core was a pretty good game considering the pedigree.  One wonders what they could do with a main line FF game using a structure like this.  Combine the parts of Mass Effect and FF that I like and create == ???

These games would be worth playing if they came out on the iphone.

I beat Crisis Core when it was released. Very good game. As a matter of fact, all PSP games are very much under-looked. A couple of other RPG's to look at also... 
 
-Crimson Gem Saga (also available on the iPhone) 
-Riviera The Promised Land (also on the GameBoy Advance) 
-Wild Arms XF 
-Y's 7, Ark of Napishtim, and The Oath of Felghana 

I stopped playing Crisis Core when I got to that stupid fucking stealth mission.

This time I dig a little deeper into the PSP vault and come out with some RPG gems that I think people should give a chance, granted they have the palette for certain styles.  Again this is one of those "Top Games" list, but some games that may have been passed over or that I want people to try. 

1. Final Fantasy Crisis Core - a mission based Final Fantasy?  The bite sized structure makes this perfect for the platform and the PSP hardware flexes its muscle here.  The active battle system and customizable skill system streamlines the game and sends you into a great variety of missions that can take you anywhere from 5 minutes to 20 minutes depending on what kind of time frame you are working with.  This is a great portable RPG and for those that complain that they don't "have an hour to play with their portable system" then put this in their hands because it will satisfy their every need for an RPG. 
2. Mana Khemia: Alchemists of Al-Revis - a hidden gem and an overlooked JRPG.  It is the lovechild of the crafting system in Dark Cloud and the social setting of Persona.  You play as a fledgling Alchemist in school that gets drawn into a typical RPG story.  Save the world (school).  The appealing quality of this game is the fact that the main mechanic of the game is being able to combine all the fat loot you find off monsters into big powerful items that aid you in your quest.  Not for everyone, but it has that crafting hook that can get quite addictive. 
3. Disgaea: Afternoon of Darkness - not a straight up RPG, but a strategy one that I think shines on this platform.  Beyond the quirky, dark humor lies a great strategy RPG that has you commanding an army across a battlegrid.  Fully customizable characters and over-the-top battles make this a great package that has so much content packed into it you could play forever.  I like this more than Final Fantasy Tactics because it is gives you more customization and control over your party members and doesn't fall into the dry-spell that FFTactics falls into. 
4. Valkyrie Profile 2 - Probably the most unconventional RPG I have played.  You play as a valkyrie preparing for the ultimate battle of Ragnarock.  You must gather your army of souls within a certain time period, which forces the player to make some tough decisions on who is going to be in your party and who doesn't make the cut.  Aside from the time-limit the adventure mechanic is also very unique.  You traverse each area as a side scrolling platformer and when you encounter enemies it drops you into a standard RPG battle screen. A great game for someone who is tired/bored of conventional RPGs and wants something different and challenging. 
5. Lunar Silver Star Harmony - The opposite of the above entry.  Lunar is as standard as you get for JRPGs but you cannot it against it because it does it so well.  The story, the characters, the world all add up to an amazing experience that you cannot pass up. Although dated, the mechanics and gameplay hold up but don't expect anything outside of the box on this one, simply a great story driven RPG classic. 

The PSP generally gets a bad rap for not having a great library and I wanted to alleviate some of that pressure.  Sometimes you have to dig a little deeper to get to the gold and hopefully I did most of the digging for you. 

Video rendition here: http://www.youtube.com/watch?v=CJTTqL0xEBo