It's not that new but newer than those "coming back" SLIM, ROUTE 66, etc. Astra.
Hosts famous local/ internation DJs every now and then. But suggest you to go on "Special dates" there (when they host famous DJ) Which usually costs 500-800 Baht for entry fee (cheaper if you buy in advance)
Check their website for an update/DJs Line up
Dress Code: No flip-flops, Bring copy and your passport
If you want to go where the locals go - this is IT.
Those who love R&B must check out Route 66. The club is divided into North, South, East and West areas with the larger areas (East and West) playing R&B music. I was there on a Friday night and it was jam-packed with young people out having a good time. Great R&B/Hip hop music with the music videos being shown on screen too. If you need a break, there are plenty of tables and chairs outside where you can sit down and get a drink.
Another club to check out is Club Astra, just a few doors away from Route 66. There are plenty of different events held here weekly - the Friday I was there, it was drum and bass which I LOVE. Cover charge applies here though.
A few other places along RCA that were worth checking out but I was quite happy spending the rest of the night at Route 66. Clubs have to close at 1am so don't head out too late! And don't forget to bring your passport for identification.
This is my cop out from loading in stuff that shows;
a. Where we go.
b. Whether or not we are up to speed or a bunch of sad, out of date lamps.
Alas, it is traditional stereotyping to consider "QBar, Bed, Faith (now renamed and getting back to what it was), Mystique (now closed) are relied on as decent 'non-teeny' clubs; Club Astra and the others on RCA being for the youngies and uni students; Vertigo being upmarket; Narcissus round the back of 23 has the politicians kids; KSR being full of travellers; the huge old ballroom types on Rachadaphisek are heaving with locals having a great night out; Soi Ekkamai on the up; Silom Soi 4.... etc. etc. etc."
And the problem with these stereotypical statements is that a decent night depends on who you're with and that it all changes around pretty. (Depending on the DJs, who is on Police Col Maj Gen Bangkoksfinestaporn's hassle and raid radar, who the new management is, and the general flow of the crowd.)
Maybe if you are in from overseas it is better to ask around when you get here OR buy Friday editions of The Nation and Bangkok Post and check the entertainment pages.