I've been to BKK so many times since 2001 I can't remember!
I usually stayed on Rambuttri Road (the quieter road which runs parallel to Khao San), but no longer after I found this gem.
It is simply the nicest little 'flat' you could wish for - air con, good bed, spotless, great shower / toilet, incredibly secure and great staff.
It is approx 3-5 mins walk to the top end of Khao San Road (burger king end). The staff are all lovely and speak perfect english. The place is clean and modern - perfect for me and my girlfr.
Price-wise it was circa £23-25 / night, but between the two of us that was a steal.
Seriously, if you need somewhere clean, secure with mod cons and comfort - this is the place, look no further.
(and no, I don't have shares in the place - it was genuinely a top place to stay - can't believe it took me 8 / 9 visits to find it!)
Oh and the map they provide you in the confirmation email when you book is useful for Taxi drivers - use it. My advice is to get the Airport Link Train to the last stop for ~THB 50 (£1) and then get a taxi for ~THB 200-250 (£4).More