In your opinion which distro is best to use with KDE4?
I tried Kubuntu but found lots of bugs with it (missing icons in kicker menu being one of the most annoying), openSuse was nice but I just cant get on with rpm's, tried Debian but at the moment due to lenny being frozen KDE4 is still in experimental and when I tried to install it screwed up my system (I'll try it again once lenny is released and KDE4 moves into unstable or testing as I love debian, apt and rolling release).
So in the end went back to Arch which I love with KDE4, had no problems at all yet (using kde4.1.2)

If you're happy with Arch, stay with it. Even though I am more of a FreeBSD guy, Arch is by far my favorite GNU/Linux distribution. Also, you get the option of using either Arch's official vanilla KDE or KDEmod.

I tried a bunch of distributions because I wasn't fond of Kubuntu. In the end, I went back to Kubuntu. I hope that 8.10 will see the end of the annoying bugs. I would just wait. Or try Gentoo. If you absolutely need an debian based distribution, just go to Distrowatch and find one.

I think it is probably a touch early to find the best KDE4 implementation as some are still in development

Having said that, I have little issue with Kubuntu and haven't tried any other KDE4 distro since probably 4.0 was released.

I love Arch Linux.

Official KDE packages
KDEmod
KDEmod3
kdesvn

Oh, oh, oh the choices to choose from!

I'd like to throw in Gentoo Linux - it has (for a few days now) quite good KDE4 packages (which are being built from the source code on your own computer, as any package in Gentoo Linux). There is also a way to build from SVN as often as you like with very little effort.

So if you have a bit of Linux experience already, love being able (but also having to) configure everything as you please, and have a recent computer (or a lot of time for waiting for the compiles), give it a try

Well I would say Opensuse even though I don't love rpm based distros. But zypper has gotten so much better with 11.0 that it really isn't an issue anymore. I like that their packages are updated often, theirs maintainers are also KDE devs which means there are from my experience more backports from upstream (such as the panel autohide in KDE 4.1.2).

Definitely openSuSE, if not just for the fact that they back port functionality, the build service, and that KDE 4 is pretty rock solid.

Well, I think that, considering current KDE development tempo, you have to choose between stability and latest packages with more options. Also, you have to consider that there is a high probability that you will not find appropriate package in repoes, but have to build from source.

That's why I like Arch: Not only you have variety of choice (there are several KDE repoes to choose from, as Zarin well pointed out), but also AUR (Arch User Repository) which makes compiling as easy as single command or two.

Also, did anyone notice that trunk works better that any distro stable 4.1.x ?

I too love archlinux, KDEMod, svn repo, KDE3 packages, shaman & arxin/tribe in the future, and a bunch of apps through AUR & yaourt for the lasy.

openSuSE has been my distro of choice since KDE 4 came out. They keep their packages updated and KDE 4 has been very stable on the openSuSE 11.1 beta 2 version that is out now.

I'v used all religions, filosofies and politicals. but in the end, I'm stuck with mandriva.
those days I'm like a **** with distros, trying 1 per week.

Kubuntu, though I may be a bit biased. :P
Intrepid will rock your socks.

Kubuntu is not the perfect kde distro, but at the moment it's the best.
If they'd replace adept with something less ugly (kpackagekit?) that would already be a huge step forward. But afterall I'm satisfied with Kubuntu.

Kubuntu is getting nicer every day. As Jon stated it will rock your socks