I've never played a MMO before. I'm not into multiplayer games or that style of combat with all the clicking and hotkeys or the quests about killing x amount of monster y.

But I've heard a lot of good things about Tera and its action combat. I've looked at Guild Wars 2 and it also looks very interesting, it looks more action too but it might be just my impression from videos.

Has someone played any of these games that can tell me about them?

How is the combat really? Or the questing? Or the main quest and story?

I like GW2/GW.

The no monthly subscription certainly helps. They increased the variety of abilities for different characters.
Though there is a bit of hotkey learning...

Yes, GW2 has no subscription, and Tera is F2P though the download is 26gb. Price is not a problem then, I'm just curious if they're worth my time.

As for hotkeys, it seemed to me like there are very few of them in GW2 and they're tied to the weapon you have on, and you can switch between two of them on the fly, no?

I just didn't want something like WoW where you practicallt have a piano full of hotkeys.

Fewer in GW2 than in other MMOs = true.
A lot more than I'm used to if it's MMO versus different genre though.

A lot of chances for pick up and play. I haven't been able to get as far as I would like to in GW2 just because of time constraints.

Also, you can jump (don't know if they have jumping in Tera).

I'm pretty new to MMOs as well and I have started playing both of these games to see which I like more and they are very different games. Tera is indeed very action oriented which I really like, its not as action oriented as Devil May Cry or anything but it is still very enjoyable combat. The problem with it is the quests are very much go kill X of Y but since its more action its not boring.

GW2 on the other hand has less action but has much more story and voice acting. So far I'm also really enjoying it although the ranger I first started playing felt like he was kinda limited. The world feels much more interesting and the lore if really good while the lore in Tera hasn't made itself as apparent yet.

I haven't decided on either of them yet though, but as someone who hasn't been an MMO fan I am enjoying both of these games quite a bit.

depends on what you are looking for:

GW2 isn't the end-all be-all that diehards make it out to be, just like GW1; but that doesn't mean it's a bad game, just like GW1. it is nitch .... high quality nitch, but still nitch.

Tera is more akin to your typical Korean treadmill / themepark MMO except that there is far less grinding, it is something akin to a hybrid between Lineage 2 and WoW.

(because that is exactly what it is: NCsoft started making Lineage 3 with the explicit intent of WoW-ing up Lineage 2's gameplay, but then AION took off (PUN) and NC wanted to do more like that and killed the Linage 3 project, however the developers still wanted to make the game so they took off and formed a new company to turn their L3 concepts into what became Tera.)

little bit of triva: it is kinda funny that you are debating between these two games because the founders of Arena-net (makers of GW1 & GW2) got pissed at NC-soft and jumped ship to found a new company explicitly to localize Tera for the US.

*edit* just re-read the OP: you will probably find both of the games highly boring if you can't adapt to hot keys and clicking. both games do have a layering to their interfaces to simulate direct action controls, but neither is actually an action game. if you are looking for actual action-mmos (that aren't hat-shooters like TF2) you are better off looking at Vindictus, C9 (continent of the ninth seal), or RaiderZ .... none of them are full on open worlds with direct action controlls, but they are close.

Go find a sale on the box for The Secret World and play that (no sub required), seriously, it's really uniquely good, though it may spoil your impression of other MMOs.

I wrote up a detailed review here and my thoughts haven't changed much
http://www.gog.com/forum/general/is_there_a_gog_guild_in_guild_wars_2/post8

I haven't played Tera so I can't help you there, but gw2 is a fun game. If you do get it, I'm Zeta Wildheart and you can find me on the Dragonbrand server.