I dunno, I personally liked the scene in book 4 when Tobias almost ate Cassie as a squirrel.
Kinda funny, when you think about it, that she got madder about the skunks than she did about nearly getting eaten herself. That's Cassie, for you.
Just as a side note, I agree with the general sentiment that Cassie/Marco tends to be more interesting than Cassie/Tobias. Cassie/Tobias just tends to make Cassie look like a hypocrite, because she supposedly likes nature, and Tobias is only doing what a natural hawk would do, and (at least in book 9) she gets peeved at him for it. Then pretty much ignores him for the rest of the series.
Cassie/Marco should have been explored more, though. The differences between them are interesting; they complement each others' weaknesses, to the point that the team would not have been functional if it had only had one of them or the other. With just Marco, the Animorphs would have been too ruthless, and with just Cassie, they would have been crippled. They needed both.