So basically I'm looking for titles that are either so unique or so timeless or have such modern gameplay that you would recommend them to someone not neccessarily looking for a retro experience with the PSP.

These are the ones I've already compiled:

• SSX On Tour (Wintersports, more zen than arcady)
• Metal Gear Acid 1&2 (Tactics-focused deckbuilder, ahead of its time)
• LUMINES (Tetris from a different timeline)
• Chili con Carnage (Shoot-Em-Up that kinda controls like og Doom but 3rd person, tbh the humor is where it shines)
• Armored Core Formula Front (You're some kind of arena robot mechanic, the battles can play out with or without your input and you mostly customize the robots in between fights)
• Thrillville (You manage themeparks, unspectacular concept but pretty unique execution)
• Me & My Katamari (A classic, you roll a ball that grows in size as it accumulates various objects)
• Dead Head Fred (Action platformer with a few flaws but decent mechanics and story)
• GTA Chinatown Wars (Drugdealer Simulator before it was cool)
• Gladiator Begins (You're a gladiator fighting to pay off your debts and later the story can branch into several directions, very satisfying gameplay loop and makes the most of its small scale)
• LocoRoco 1&2 (The sidescroller for people who don't like sidescrollers)
• Daxter (Classic 3D platformer, many little features to keep you hooked)
• MediEvil (Classic Hack & Slash, nice atmosphere and some high quality jokes)