Here is something I wrote up for our Yahoo Group in response to a similar question. Hope it helps.
I have alot of machines. Let me try to sum it all up for you:
Sizzix Big Shot
If you like to cut chipboard, felt and nontraditional materials like that you need a hefty machine like this. I would say get this versus the Sidekick or the old red Sizzix machine becuase this takes all sizes of Sizzix dies and is the easiest to use in my experience. They have some exclusive dies from Stampin Up now and some cute designs like Hello Kitty so they are responding to the market on that. I also am really liking their embossing templates -- got a couple of them recently. Every November the Ellison warehouse in Irvine, CA has a big sale on their stuff--that is a good time to get your machine for a deal (that is when I got mine and most of my dies).
This will take ALL dies, including QK dies, with the use of an adapter.
Dies cost about $15 and up, depending on the size. Machine is about $50.
I heard the Cuttlebug is good and takes alot of diff dies but me and ProvoCraft don't get along so hot (they burned the LSS's when the Cricut first came out and I still have not totally gotten over that) so I have personal issues when it comes to recommending their products. Just being honest here. If money is an issue I would say do this one because you can use a coupon on it at the box stores and their dies are relatively cheap with Coupons . It will cut very thin chipboard -- I've seen Cindy Fahrbach do it.
Dies are about $7-12 depending on what the style is and sometimes they come in multi packs. Machine is about $40 with a coupon I think.
QuicKutz (SQUEEZE AND REVOLUTION)
These are the most expensive however, they have been marked down because they are discontinuing them. They have a new machine coming out that is supposed to be motorized and will take 12x12 dies. Plus the Revolution is victim of some labor dispute in China so they are not shipping them right now.
At any rate, I love my QK stuff and have the whole system.
Squeeze tool takes dies 2"x2" so the images are really small. It is lightweight, easy to transport (not like the Sizzix or Cuttlebug which are heavier) and the dies take up little space (but they can get heavy if you have hundreds of them). Drawback is the dies are small and it does take a tad bit of muscle to use.
The Revolution takes 4x4 dies, a set of one to four 2"x2" dies at a time or you can use the 12" platform (sold separately) to cut 12" borders and 4x8 alphabets. They have gotten alot more competitive on the pricing of dies with the 4x8 alphabets at just $40 but they are still pricey when compared to other tools.
QuicKutz just came out with plastic, adhesive sheets, white chipboard, and some other fun materials that can be cut with the Revolution dies. I have some just have not put it to the test yet.
The best part about QuicKutz is that they have excellent customer service, an excellent reputation, and a good quality product. If you have any issues, call them up and they will fix or replace your machines or dies. No other company does this.
Plus there are TONS of dies and designs to choose from--I only own about 1% of what they have on the market and I have a pretty decent collection myself. Dies range in price from 6.99 for a single 2"x2" die up to $199 for a cookie cutter style alphabet.
Revolution machine is under $50 at just about everywhere now and the Squeeze is around $20.
if you remove the foam from the dies you CAN cut felt and fun foam with them too.
These are just more versions of diecutting machines you can get and they all have their own dies. Most dies these companies offer can be used in the Sizzix or Cuttlebug with an adapter. Spellbinders dies can be used in the QK Revolution. Spellbinders dies come in sets for about $25 each.
Wishblade (Xyron), Silhouette (Quickutz), Craft Robo
These are all the same basic machine, just made by different makers. They all use the same Craft Robo software with some various upgrades, like some machines you can weld words (link all the letters together to cut out as one shape) and easily make shadows. They all retail for about $200-350 each. You will need a computer to operate these machines. The software is not always intuitive so you might need a class or some help to get started but if you are just a little computer savvy it should be no problem getting started.
Maintenance on these machines is the cost of replacing blades and mats. Blades range from about $10 each (just metal part of blade only) up to $45 each (blade with full assembly package). Mats range from $10 each to $25 for a pair depending on the manufacturer.
The upfront cost on these machines is high but once you have the machine, you have access to an infinite number of free fonts online that you can download and cut to any shape or size. Also you can buy shapes from other people who make and sell them, buy shapes form the manufacturer, or even make our own shapes. There is alot of versatility in these machines but you have to be willing to work on the computer.
These machines usually just cut paper and cardstock -- any other materials may damage the blade or wont cut all the way through. I have a QK Silhouette I am happy with and another friend has a Wishblade she loves.
Pazzles is more pricey (starting at $300 up to about $3000) but it will cut chipbaord. It is basically the same as the other machines otherwise. I have the Pazzles software and think it is difficult to use.
SILHOUETTE SD (Quickutz)
This is a Qk Silhouette that takes an SD card like the Slice. I tried it out at CHA and got it--just haven't taken it out of the box yet. Basically you use the computer to load shapes onto the SD card at home. Then you can take just the machine and the card to a crop and cut all the shapes loaded onto your card.
This is made by Making Memories . The machine is about 5" cube in shape. The shapes it can cut are super cute. Goes up to 4" tall on shapes. The bag it comes in is super cute too. It takes SD cards so storage is not an issue. Also it can be operated without a cord in case you go to crops alot. And it does not require a computer. You have to hold it while it cuts which is a major drawback. It comes with a glass mat that you have to apply adhesive to in order to cut your paper on it so that is a bummer. It is like an alternative to the Cricut.
You can cut paper and cardstock with this but also MM sells acetate and some other materials you can cut with the Slice.
I have not used this one yet but heard good things about it. It requires a computer as well and works kind of like a Wishblade .
CRICUT (by Provocraft)
The Cricut has two sizes -- the orignal which cuts 6x12 and the Expression which cuts 12x12. You CAN cut chipboard with the Cricut if you buy a special blade but I have heard that people are not very successful unless it is really thin cereal box type chipboard. You can also cut paper and cardstock with this machine.
The Cricut costs between $100 for the small one up to $300 for the Expression. Cartridges are about $40 on sale up to $80 each. You have to buy a cartridge to get new shapes and fonts so it is alot like a manual diecutting machine in that way. If you don't like computers Cricut is the next best thing to a Wishblade since you just type out what you want on the screen. It is bigger than a Wishblade or even bigger than a printer but you don't need a laptop to use it so that helps with space issues while using it. There are TONS of cartridges out there for it too but you will find yourself spending alot to get a good variety of shapes. And it is made by Provocraft who I don't really like. Again, just being honest here!
Blades are about $10 each and so are mats.
Hopefully this helps you in your decision. If you can wait, take some time to try out the machines at stores when they have demos or ask a friend to bring theirs to a crop so you can try it out. That way you can see for yourself if it is something you will use before you invest hundreds of dollars.