Kotobuki Hikari

Hikari is the most apparently 'normal' of the heroines that have routes splitting off from the common route. She is in love with the protagonist from the beginning, so them getting together is mostly a matter of the protagonist getting over his self-derision. Her route's drama is intensely personal, though it isn't a relationship problem... The route itself has a lot more ichaicha than any of the other routes, so I felt like puking sand several times during it... but for people who like that kind of thing, it is an ideal route.

Hanasaki Nonoka

The protagonist's little sister by marriage, an adorable girl who is referred to as a ダメ人間製造機　or a machine that makes men worthless, due to her tendency to spoil her older brother rotten. To be honest, since her route is listed as an afterthought, I thought it really would be... but it was easily the most emotionally touching of the routes so far. At least part of this was the fact that so much of her route is written from her point of view, rather than just the protagonist's with a few parts at key points. The route starts a year after the events in the common route, and it assumes that the protagonist didn't choose any of the four main heroines. Like many imouto routes, this one's drama is in the actual formation of the relationship, rather than after it.

In terms of the ending, this one is the most satisfying so far, if only because Nonoka gets developed at least a little bit throughout the rest of the VN, including the other heroine routes...

Koutsuki Kanna

Kanna is Wakaba's maid. She is a bit two-faced... or three. First is her 'gentle-mannered maid' persona, second is her yuri-yuri 'I love Wakaba' persona... and last of all is the delinquent, rough-talking side she only seems to show to the protagonist. Her path was the most surprising of the heroine paths, which was a good thing in some ways. I'd expected a more conventional plot path, but this was a good change, considering how predictable the other paths tended to be.

True Path

It isn't so much of a path as a means of giving closure to the protagonist's own personal issues without the intervention of a heroine and H. Precisely because of that, this blasts all the other routes combined out of the water in terms of emotional impact... but it also highlights how completely Saga Planets failed to bring forth its usual flair with the heroines. Nonetheless, this also gives the best ending in the game, with them showing the heroines and the protagonist quite a bit after the story is over and describing in detail what the protagonist, at least, is doing with his life and his attitude toward it.