She's smart, cute, funny, gets you outta jams, dresses conservatively girly and not like a whore, and more importantly she kicks MAJOR ASS! She will actually take out Combine, Zombies, and "Zombines" unlike other companions who just miss.
She's not one of those companions that's telling you to "hurry hurry hurry" and make you chase after them and rush through the game. She will politely wait for you to finish exploring an area or apologize if she's in your way.
I find myself apologizing if I accidentally shoot her where as for other companions I wish I could kill them.
I like Alyx.... I like companion cube.... and I like Ghost.... but which is better?.... There's only one way to find out..........
(Only UK folk may get this) ;P