私たちは=watashitachi=we
お客さまに=okyakusama ni=by customers
ご満足いただくこと=go-mannzoku itadaku
koto=to be satisfied with
一番大切に=ichibann taisetsuni=most importantly
考えています=kanngaete imasu=consider
The Japanese expression above is one to be used when you address directly to your customers. When you just state your business policy to a third party, the phrase should be as follows:
「当社はCS(顧客満足度)を最優先事項としている。」
Hope this helps.

The former answer is very good.

But I would like to show you a shorter and more polite one.

Watakushidomo wa okyakusama no gomanzoku wo daiichi ni kangaeteorimasu.

Watashidomo = we; modest wording
Daiichi = most important matter
orimasu = modest wording for imasu

I work on ISO 9001:2000 version. The customer satisfaction is emphasized.
You also use 'okyaku sama wa kami sama dsu' as well (literally: customer is the god)

This is the same as Soonthon Lupkitaro's suggestion above but I am giving you the Sino-Japanese characters.

If your browser is Japanese enabled then you will be able to see the characters below.

顧客満足優先

If not, you will be able to see them as a gif image at the URL below (please copy the line below and paste it to a browser window).

http://www.mii.kurume-u.ac.jp/‾leuers/kokyaku.gif

The advantage of this suggestion are
1)that it is a standard word-phrase.
2)that also looks like a motto which would stand alone on a web site or letter heading.
3)It is all in ideograms (Kanji) and is thus "nice to look at".

The other suggestions above are good renditions in sentence form.


Examples of the use of the above are at

http://www2.cnet.ne.jp/asp/aspnews53.html
Where it is used next to "Customer Service First"

and at
http://www.chusanren.or.jp/cgi-bin/seminar-data?seminarnum=4...
Where it is contrasted with putting the manufacturing first (Seizou Yuusen).

The word breakdown is
Kokyaku = Customer
Manzoku = Satisfaction
Yuusen = Put first, Prioratize

If you did not need the characters or could figure them out yourself, then please give the points to Soonthon Lupkitaro.