So if I have the standard GoT LCG core set with the 4 big families, what would you recommend would be a first expansion pack to get?

It depends.

How have you been playing/do you plan to play the game -- Competetive in Tournaments & Leagues? Melee/Boardgame style (one person brings pre-built decks for all players, with little customization) with buddies? Do you want to add the other two houses (Greyjoy & Martell)?

Playing casual non-tournament joust.

So are the two other houses an obvious choice?

Common recommendations include:

A second Core Set (so you can play Duplicates of some Unique Cards, and get another of some auto-includes, like Valar Morghulis, Wildfire Assault, etc).

The first Cycle of Chapter Packs (A Clash of Arms) has lots of good cards.

Martell & Greyjoy -- again, it depends. How much variety are you looking for? Do you currently have a favorite house? Do you have a favorite mechanic or playstyle?

I'm still in the infancy of the game so its a premature question I guess. But I just wanted to get a gauge on what's popular. Is it the case that Martell and Greyjoy aren't made anymore?

No, everything is still either in print or being reprinted - they haven't stopped making any of the LCG.

For any new player that is interested in trying all of the houses, I'd most certainly recommend a 2nd Core Set and Princes of the Sun and Kings of the Sea expansions.

With the 2nd core set, I'd recommend building decks using this as a guide:

http://www.cardgamedb.com/forums/index.php?/topic/207-4-decks-built-from-2x-core-set/

This is mostly because the two deluxe expansions I just mentioned are generally better than the preconstructed core set decks, so this should help try to even the playing field a little bit when involving them.

I knew i was going to focus on House Greyjoy from the start, so after i got the Core, i got Kings of the Sea and most of the packs from the "A Song of the Sea"-cycle which contained alot of "boaty" cards

http://www.cardgamedb.com/index.php/GoTCards.html/_/a-song-of-the-sea/reach-of-the-kraken/

http://www.cardgamedb.com/index.php/GoTCards.html/_/a-song-of-the-sea/the-great-fleet/

http://www.cardgamedb.com/index.php/GoTCards.html/_/a-song-of-the-sea/a-turn-of-the-tide/

http://www.cardgamedb.com/index.php/GoTCards.html/_/a-song-of-the-sea/a-journeys-end/

Thank you all for the input

If you decide to buy an extra Core Set, Kings of the Sea, and Princes of the Sun, I have the cards for all of those (got them as part of a big trade) that I could sell you without the boxes.

Here's the unofficial buying guide.

Since I play by myself atm. I am thinking of getting Princes of the Sun first. Does anyone have a set of core set cards for sale? After that, I either would like to buy another core set or get the Kings of the Sea expansion. For some reason I want all six houses first.

This has been a huge debate on some forums.

Why waste money on a second Core set that will be obsolete in less than a year's time? If playing casually, you can always make colour copies on card stock of whatever additional Core set cards you might need in your decks (and use opaque sleeves so that the copies can't be discerned from the originals in the deck), or else use other cards as proxies.

I think that for new players who absolutely want to start playing this game before the release of the second edition later next year, the 6 deluxe house expansions are all worth picking up… but additional Core sets and chapter packs? Probably not worth it at this stage in the life of the game, especially if you're only playing casual jousts. But that's just my opinion...

I disagree, and I don't quite understand the logic. If you're playing strictly casual, no 1ed product becomes obsolete *ever*. Cards only become obsolete with regards to tournament play. In casusal play, cards can and will be used as long as players are willing to play the game. I don't regard the standalone board games I buy as "obsolete" just because there will not be any expansions forthcoming. For example, I own the War of the Ring 1st edition board game. Is it "obsolete" just because a 2nd second edition has since come out which I don't own? Can I not play it anymore? What is different for people who own some 1st ed AGoT LCG cards and only play locally and casually with them? I know game groups who still play AGoT CCG and other discontinued collectible card games locally.

Sure, if people plan to ditch their 1st ed cards when 2nd ed comes out, and buy into that one, that should inform their decision on what 1st ed cards to buy now. But I don't think it's necessary to discourage anybody from buying a 2nd core set now. It's as good an option to expand a card pool as it ever was. People just need to keep in mind that no more new 1st ed cards will be forthcoming from mid-2015 on, and that 1st ed tournaments will slowly fade away. They will need to make up their own minds what conclusions to draw from that knowledge.

The gist of it is this: A second core set is a good option to expand a new card pool, especially if several players have to be supplied from that one card pool. It is not compulsory though - it's just as possible to buy deluxe expansions or chapter packs first, especially if you're prepared to use proxies for the CS cards you need more than one of.

Personally, I don't like to use proxies all that much. Even though I have a very large card pool (I own at least 3 copies of every LCG card ever printed, and of the vast majority of cards I own 6+ copies), I need to resort to using proxies of some cards for casual play, because in addition to the ~5-8 decks I have usually built at the same time, I have a draft cube of 1100+ cards permanently built. But I try to avoid proxies as much as I can. People need to decide for themselves how much proxying they can stomach.