I started out with Resident Evil 5 which I found to be overall disappointing, poor experience.
Resident Evil 5 is only good for its co-op. Aside from that, I'd agree that it's a pretty unremarkable action game.
But I decided to give RE6 a shot since fans were saying it was so good and the pinnacle of survival/horror.
I can't imagine anyone saying that RE6 was the pinnacle of the survival horror genre, let alone the series' own fans.

The xbox version only got 67/100 on metacritic. It svcks.
Now people are telling me that RE4 is definitely worth playing but given what I've played of the RE series so far, my stomach turns at the thought of playing another entry. The gameplay videos look largely similar to RE5/RE6 complete with "action zombies." So why is it held with such high regard?
First, let's get one thing straight: RE4 is still an action game, first and foremost. I don't think that's very mistakable, even though a lot of fans say it's horror first (mostly because of the name, I think).
But, RE4 is still a very, very good game. The gameplay is tight and refined, the characters are likable, there's a good sense of progression, the story is cool and contains a lot of twists, and it has a nice finale. The only low part of the game is its dialogue, which is oftentimes a bit goofy, but I found it rather endearing.
I know you've had a bad taste with the Resident Evil series so far, but believe me when I say you haven't seen the nice side of the series. In contrast with a lot of the games you've played so far, RE4 was actually critically acclaimed; it got a 96/100 on metacritic, after all. So if you're going to play any game in the series, play this one - you probably won't regret it!
