Definitely VMWare.
I test very many different virtualization software for various reasons although I had already worked before heavily with VMWare. VMWare is in my opinion by far the best software in this area and supports also most operating systems and settings. Also you will find a very stable product with it.

In my company I am using mostly VMWare Workstation and VMWare Server, where the first one is not free but offers some additional nice features.

For some testing and playing the free Server product should fit your needs easily, also the VMWare Player is free and should be tested.

Privately I also bought a licence for Workstation as I am doing a lot with it in my freetime and can therefore fully recommend it although it is a little pricy but not too expensive.
On the official website or even at Wikipedia you can get an overview on which features each version offers and for what they were designed.

Depending on your needs I think the Server product would be fine for you.
If you have any specfic questions please feel free to ask.

Hi All,

I can also recommend VMWare as the standard.

I am however a little less repulsed with Virtual PC Beta which is now imbeded in the new Windows 7 after a windows update  . It finally has USB support but the integration feature is still a little buggy.

I am also a big user of Sun's Virtualbox which does pretty much all I need for a desktop and I would rank it above VPC but below VMWare.

C

They're in the middle of a series about virtualisation and ESXi on Hak5 (it's been advertised here).  I'm not an expert, but I think that they're aiming more towards a functional virtualisation setup for a real working network, rather than a lab to play and learn.  They built a PC last week for under $2000 and they loaded ESXi.  I'm not sure what comes next, but I hope that they'll do some of the configurations of ESXi and OS installs.  I suspect that I'll be following their recommendations over the next month or so.

I know that such a PC would exceed my lab requirements, but I could use it subsequently in a production network.

A little late on this one, but I also vouch for VMware over VirtualPC. It has been a little while since I tried VirtualPC, but I really disliked it compared to VMware.

If you're going to be getting a system to run this on, you may want to consider the ESXi version (the fact that it's free doesn't hurt either ). I'm not sure I saw anyone answer your question.. the difference is that VMware Player/Workstation/Server all run within an [host] OS. The VMware ESXi is more of its own, very minimal, operating system on which you can build virtual machines (at least this is my understanding of it - I've never installed it, so someone please correct me if I'm wrong). If you go that route, make sure the hardware you purchase is compatible.

BillV

So from the sound of it, ESXi is the host OS?  I didn't look into it's compatibility, but I don't have much option on the hardware.  It's a machine that I'm building in class, so I get what they give me.  It's not gonna be the greatest, but I should be able to get it working well enough between what I get and what I have hanging around.  I'll have to look into it more to decide if want to use ESXi or Server.  But at least I've gotten VirtualPC out of the way.  Thanks.

Yes.  ESXi is it's own base operating system.  By doing it that way, they've assured that the VM's have much more control and access to both the physical hardware and resources than they'd have if running underneath another host OS, such as Windows or Linux.  It's really very easy to install (bootable cd image,) once you have hardware that supports it, and installing and managing guests takes very little understanding, as well.  There are a few options you might spend some time on, with some of it's internal routing configs, etc, to give hosts NAT, Bridged or internal VLAN's, but aside of that, I think you'll find it very easy to work with.  The ONLY drawback to it, at all, is that there's a bit of effort involved if you want to transfer, say VMWare Workstation VM's to the server, or vice-versa, as there's a bit of translation that occurs, however, if you truly want a server, it's not as likely you'll be moving VM's around.

IF you plan to run the VM's where you can 'easily take them with you,' then I'd advise VMWare Workstation (which I've also been running since VMWare's earliest revisions.)  Now, it does run under a guest OS, so hardware access is more 'tainted' based on what the host OS allows the VM's to do, etc, but VM's are easily portable between HOST machines, and even between multiple HOST OS's (such as Linux and Windows) with only minor tweaks involved.

So it ultimately depends on how flexible you want to be, whether or not you want a system that's very similar to what larger, production customers run, and what type of hardware or portability you want.  Regardless, I prefer VMWare to the other options.  It's always just been way simpler to get things done, way more functional, and again, tends to be status quo for customer environments I've been in.

I didn't plan to get this little project of mine going for a month or so, but an opportunity came up that required me to start a little sooner than I expected.  I planned on using a separate machine, which had me leaning towards ESXi.  But since I don't have that extra machine yet, I'm using Server for the time being.  It didn't take to long to figure out, and it's been working great for me since.  Thanks to everybody who helped narrow my choices down.