Kumo no Mukou, Yakusoku no Basho, Umi ga Kikoeru Recommendations
The first half of TPPiOED is a lot like Ocean Waves. There's a love triangle, where two guys (one with glasses, one not) get involved with a girl. The girls in both differ greatly, Ocean Waves' being very selfish, but you'll watch both and have similar feelings.
Unlike TPPiOED, Ocean Waves doesn't turn into a sci-fi mess half-way through. That's why I rate Ocean Waves a lot higher.
In terms of other Ghibli titles, Ocean Waves is very similar in execution and 'feel' to Only Yesterday and Whisper of the Heart; two of the more mature Ghibli releases.