But ever since 3 just released I been noticing throughout the interenet  that the way the story ended was really bad. I'm big on stories in video games so would it be worth it for me to play the series or does the ending ruin the gaming experience?

PLEASE NO SPOILERS.

yes, the first one is self contained. sort of like the initial matrix (actually compare the whole trilogy. (I liked the whole trilogy but a lot don't so thats why I'm making comparison)

The second is kind of... not much plot mostly character based, though it sets it up for 3.

Does a 3rd bad sequal (story wise) ruin the whole series for you in anything else? Like ending to tv show. etc? If it is then maybe don't play ME3. But then again, I thought the whole story of the franchise had issues after the first one (though I liked ME2 the best), and the ending had issues but I thought the whole ME2, and ME3 had issues story-wise (though I think most games do, even ones that are acclaimed for their story :P).

So far so good for me. I havn't gotten anywhere near beating the third game. It's gonna be about another 3 weeks until I get there at the rate I'm going. I enjoyed the first one, though it's not something you should be doing sidequests on (The side quests become the same after a few missions). The second one has a "good" story. But most of the story is character based, which I really liked cause a story's useless without good character development and Mass Effect 2 has in spades. Mass Effect 3 plays a bit more like the first and so far reuses Bioware's plot devices that they use with their games so I can see why people are complaining about its story, but I really like it so far.

Play the first game and then watch the ending of the last game, nothing interesting happen in the middle really.

Mass Effect is probably the greatest trilogy to ever grace consoles.  Some people hated the ending but that holds true for all endings.  I personally loved my ending and I worked hard to earn it; I worked hard in Mass Effect and Mass Effect 2 to make my endgame scenario even possible, and in Mass Effect 3 it all came together.  It makes you think and makes you want to play it all over again, right from the beginning, to make new choices just to see how things pan out.  That's something that no other franchise offers yet.

well if you enjoy the game up until the end you will until then :P

I don't see how the ending will ruin the fun of the past hours you've played

I mean how could it possible end? Shepperd dies after saving the world? (I don't actually know what happens)

Play the first one, it has the best story and best ending.

I definitely say buy them. It's a fantastic series. In my personal opinion:

Mass Effect 2 = Mass Effect 3 > Mass Effect 1