Some of them look all right, but there just doesn't seem to be much uniformity between them. Some are drawn in completely different styles than others. The ones I think work pretty well are
The rest I really don't care for. The eyes are too small and too perfectly round, and all of them look surprised.
The <3 doesn't look so much lovey to me as it does stalkery, your rolleyes looks more like it's daydreaming, and your angry face looks kinda like a tomato from Attack of the Killer Tomatoes.
The one I absolutely hate is :4ch:, which by the way that face was made at SomethingAwful, not 4chan (and I wish the person who first made it would die in a fire).
Not to mention using .png means no animation. There is an animated .png format but not all browsers support it.
I think we should just take the current set of emotes and alter them to add new emotes. There's nothing wrong with the current ones (except for ).
I hope you don't take offense to my criticism, I'm just keepin' it real bro. Like I said, I usually love your stuff.