Well, let's start with the ones I really really like:
Gogoat: Let's start with this: I love Grass-types and I am quite fond of caprines. Took them far too long to generate a goot and I rather like this one's design - minus a few subtle elements such as the weird bear nose and the rather illogical horns (although those were clearly needed for the Card Games on Goatorcycles effect). Transform and bleat out!
Clauncher: I'm sorry, but pistol shrimps are more awesome than your face. It had better get an awesome evolution.
Honedge: This gen's Artifact Creature, and a -really awesome- one at that. Even if it totally is a Soul Edge expy, its typing and ability make it appear to be pretty damn incredible, and if it has the stats to match? Yeah, totally having one.
Noivern: I've been in love with this thing from the moment I saw it. It's a fricking Fruitbat Wyvern. What's not to love? (Other than its rather generic Dragon/Flying typing, alas).
Things I'm interested in but not as much:
Talonflame: There's a lot of potential to this critter - I like its general design and love the fire/arrow/peregrine falcon/speed theme (and the fact that its pre-evo is a robin. MOAR LIKE ROBIN HOOD AMIRITE) and if it has the physical attack stat to go with the speed they keep promising us, Talonflame may be fricking awesome.
... But seriously why did they have to give it those red blotches on grey. It looks like it has a skin condition and really needs to do something about it. It's better in the art, but ingame the poor thing just looks DISEASED.
Certainly sounds Diseased. With a name like Talonflame it clearly suffers from a bad case of N00bfanmaditis.
Maika and Calamanero: I am so, so torn about these guys. On one hand they're fricking squids (took them SIX GENERATIONS TO GIVE US A FRICKING SQUID! ><), they have an awesome as hell type combination and the idea behind them is nifty as hell. On the other hand, their designs leave MUCH to be desired. Does any of these fucks at Game Freak know HOW THE HELL CEPHALOPODS WORK? Clearly not. I mean, at least they had the sense to give them a beak. But they put it in the way wrong freaking location. Tl;dr, their awesomeness as squid thingies is damaged by their sheer nonsensicality. Ah well.
Goronda: Oh hey, we finally got an actual badass mfking bear. Shame about the pre-evo though. I can't stand Pancham and its little asshole face. <<
Xerneas and Yveltal: I want to hear more about their myth and story, what with the Life and Death theme they seem to have going on. I'm fond of both Knifeleg Crystalneuronantler Deer and Flying Bacon of Doom relatively equally. The reason they're only listed in my 'sort of interested but not quite' angle, though, is the fact I never use Legendaries.
Things I have POTENTIAL interest in, but still waiting for evolutions to confirm.
All Three Starters: Frankly I find all the starters a little lacklustre this time around. When We'll see what they evolve into, I might develop an opinion.
Litleo: Okay, Litleo itself is fucking derp. But what catches my vague interest in it is its tail - specifically, its shape. It reminds me somewhat of a scorpion tail and this suggests that this thing might evolve into some kind of a flaming manticore of badass. Now THAT I would be very much interested in. Unfortunately, I doubt Gamefreak will be that creative, and we'd likely just get a generic shitty fire-mane lion of the sort every other n00b has in their region. We shall have to wait and see.
Helioptile: These things look derpy as hell and apparently you encounter them by stepping on them accidentally? (avoid stepping on small lizard). However, they ARE frillies, and they have some pretty awesome evo potential too. Hopefully into something REALLY cool.
~ 
)
), and X will be second. Sorry, but I prefer birds of doom over fairy reindeer with Christmas lights any day.