If you're looking for a decent strategy RPG with a truly old school feel, Tactics Ogre: Let Us Cling Together might be the game for you.  Originally created in 1995 for the the Super Famicom by Quest, the game has recently been remastered for the PSP by Square-Enix.

Due to the death of the king and the lack of a true successor, the recently obtained peace of Valeria has ignited into full blown war. As the Hero of Golyat and the leader of the resistance it's up to you to acquire and train soldiers capable of regaining the peace of your isles.  Beware the choices you make. The loyalty of your soldiers will drop if they don't agree with your decisions; if it drops too low they will desert your army.  The enemy units are pretty intelligent, and provide a worthy challenge throughout the entire game. The musical score is amazing. The characters are lively and vivid. Their are multiple endings and side quests, and the best part is due to the "World Tarot", which you can keep your levels and items while you do them.  The game is almost perfect, a fact reflected by the majority of video game reviewers seeing as how across the board it's received a 9/10 rating.  The game's one true blemish exist within its level up system.  Instead of leveling up individual characters, you level up the class itself. This means any time you receive a brand new class you must train it from level one, while fighting enemies on par with the rest of your units. However, if you're someone who's been looking far and wide for a decent game for the PSP I whole-heartedly recommend Tactics Ogre: Let Us Cling Together.