Cherrim was a great design. Although not very good in competitive battle, the little thing captured the learts of all cute-loving Pokefans when the sun shone on it. In fact no one ever expected Cherrim to have a closed flower form when Pokemon Diamond/Pearl was released. Not many people liked it either.
To see Cherrim bloom and showing its adorable face in the game itself was pretty damn rare. For one, your opponent had to have a Cherrim in his team. Two, that Cherrim, in battle, facing you. Three, hope that your opponent uses Sunny Day, which, most of the time, he won't. Chances are greater when battling a human opponent, but like I said, Cherrim's not that useful in battles, so who would bother?
Cherrim's Pokedex entry in all Generation 4 Pokemon games used the Negative Form(e) sprite (closed flower), and when viewing different form(e)s of Cherrim, the game lets you see male and female Cherrim instead of Positive and Negative. Both are exactly the same non-adorable shriveled weed, down to the last pixel. Why did they bother with the male/female thing when there's a much more obvious form difference?
That's when Gen 5 came in. This is Cherrim's Pokedex entry in Pokemon Black/White
Cherrim finally sees the light of day! Instead of male/female, B/W gives us the correct ones, Positive Form(e) and Negative Form(e), instead of male and female closed flower buds completely indifferent from each other (note: I'm really averse to the word 'forme'. Sounds very wrong).
You can choose which form(e) to place on the Pokedex's front page. Common sense dictates that adorable, smiling, pink Cherrim goes in front. You even get to view their animations, both front and back to (as with every other Pokemon)
