Having just completed Ratchet & Clank Going Commando and being slightly disappointed by the experience (especially compared to how fun R&C 1 was), I randomly popped in my unplayed copy of Klonoa which I bought two years ago.
Wow. This is the kind of game I needed!
It reminds me of Yoshi's Island, a game which I feel is one of the best platformers ever. The 3D environments look great and the gameplay is light and fun, but you still have to spend a little effort to "complete" each area. The music is spirit raising and the sound effects are spot on.
I had planned on just playing it for a few minutes to see what it was like, then moving on to Final Fantasy Tactics. A few hours later I was still playing. Last night I sat in bed with my PS1/LCD, cuddled up with Klonoa.