Ubuntu Karmic on "couch surfing" laptop (this is probably the PC I spend most of my time on)

Win7 RC 64bit on gaming desktop (gonna upgrade to a retail license Win7 Ultimate - pricey but it's only $20 more than Pro to not have to reinstall everything...and it's my only "current" Windows PC so I can afford it)

Xubuntu Jaunty on file server / torrent box

Got a couple of XP VMs in VirtualBox - basically old computers that suffered hardware failures but have been converted to VMs good for playing games that won't run on Win7.

Got an old 98SE notebook I use like a console for "retro gaming" and emulation

And I got another old desktop running Xubuntu Karmic that I have no space to actually set up

Oh office PC is XP SP3.

Family's PCs:

Sister's netbook: Ubuntu Jaunty
Mom's laptop : Ubuntu Karmic 64bit / Win7 Home 64bit (never used...came with it :-\) dual boot
Dad's (work) laptop: XP SP3
Dad's (gaming) desktop: XP SP3

A variety of Windows 7, XP and even 2000 depending on machine, circumstance and day of the week

Ubuntu 9.10 Karmic and Windows 7 Ultimate

I think it's mostly been improved, especially wireless networking, but the new Ubuntu Software Center is just the Idiocracy version of the old Add/Remove Software app. The old app is far faster and more convenient. The new one is good for people who can only hold one thought in their head at a time.

Desktop/Gamer - Ubuntu 9.10
Wife's Laptop - Ubuntu 9.10
Son's desktop (uses for games) - Ubuntu 9.10
Daughters desktop (hardly uses at all, she's 5) - Ubuntu 9.10
8" Netbook - Ubuntu 9.10
2 1U Rackmount servers: Debian GNU/Linux Stable

Soooo... yeah. Lots of Koala's here . I've used pretty much any distro of linux that is downloadable over time. Not a single real windows machine in my house anymore... thank god.

Did load a windows VM for the wife that she was so sure she'd need...... she never uses it now.

Desktop: Gentoo (gentoo is rolling release so no version), plus a Windows 7RC1 partition for games.

Laptop: Windows Vista (to be W7 soon) / Arch Linux (again, rolling release so no version).

Then I have 2 Ubuntu server VMs, an XP vm and an Arch linux VM running under Opensuse 11.1 64bit + xen.

Fedora 10 on the laptops and Fedora 11 on the workstation

Ubuntu 9.10 on desktops at home and at work.
OpenSolaris 09.06 with ZFS RAID on my NFS media file server.
Ubuntu 9.10 with Rhythmbox as UPnP server and Moovida as media center on my HTPC.

My laptop boots windows XP but hard-drive has an additional ext2fs partition.

I boot debian 'Lenny' version of Linux via a USB stick (4gb) and persist changes to the ext2fs.
http://wiki.debian.org/DebianLive/Howto/USB

I also use a custom Slax version of Linux via a USB stick (1gb) too.
http://www.slax.org/

Don't need Linux installed on target pc and I can take my installation with me via USB stick

- My laptop: Multiboot Debian Sid + Ubuntu 9.10 + Vista (was preinstalled.., not sure it still works)
- My girlfriend lappy: Ubuntu 9.10
- 256Mb RAM Laptop: Debian Sid as webserver/wiki/upnp server/..