Mamoswine is a Ground & Ice type and fully evolved form of Swinub, also Mamoswine has a really amazing design, literally nothing bad about it at all, at least to me. As well, Mamoswine is another solid pokemon to play with as it has amazing stats/movepool/abilities. I honestly have nothing bad to say about Mamoswine at all, it really is a very well rounded pokemon, and making this decision wasn't easy, but I feel the same way with all of my top 10 in terms of nothing being bad at all with them, so just went off of appeal, and Mamoswine just didn't quite have as strong of an appeal over the other 9.
9th - Gliscor
8th - Luxray
7th - Electivire
6th - Drapion
5th - Weavile
4th - Infernape
3rd - Togekiss/Glaceon
2nd - Togekiss/Glaceom
1st - Lucario