Note: I originally posted this in the "Art Scene" forum, but decided to post in in my journal also for future reference. All about art markers: Prismas, Copics, Neopiko, and Fiber-Castel. May update this as time goes on. Spread the word !!

Update: Revised links for Neopikos' merchants.

First off, markers (or any popular medium) will NOT make your art better instantly. You suck now, you will suck no matter how much money you (or your parents) throw on tools.
Second, only buy if your serious about actually learning to use your sought after medium, not because your favorite artist/studio/circle uses it (I'm looking at you "manga-ka" wannabes/ anime-tards especially).
Third, color theory, learn it and USE it. Chances are your art idols use these guidelines to make their art look good.
Fourth, art is expensive. It's up to companies/stores to set the prices. I'll include some tips to get a good deal on some types of markers. Otherwise, start saving.
And finally, don't expect to have perfect use of your new markers the first time. It takes time and practice to learn how to use them effectively.

Understood ? Now on to the the marker lists and tips.

Prismacolor markers. Widely known and a good starter brand. Double nibbed (thin point and broad), bight, saturated color, blends well with other prismacolor mediums and a lot of color choices. However they are overpriced at times, tend to bleed, short life and prone to fading overtime. The best place to to get them cheap (as in less than a $1 per marker in sets as of 10/7/08) is eBay.

Copics. Ah yes, Copics, probably the most popular of the marker world. I admit, I do love this brand myself. The Alcohol based ink allows for layering and excellent blending. Over 144 color choices, refillable, create custom colors and the Sketch line's brush nib is just superb. Now for the bad; for one the price. Expensive little buggers aren't they ? Plus these markers are what I call "picky", you need to find a good brand a paper depending on what coloring style you use. My main annoyance (from personal experience) is the colors come out looking a tad faded/pastel looking sometimes. And the airbrush system, OVERRATED. For the price and preparation you might as well get into -real- airbrushing. But if you choose, it's your money.
Again I recommend eBay for good deals. But a good place to buy them is copicmarkerS.com (aka periodstyle). They have decent prices and have pretty much every accessory for copics.

Neopiko/Deleter markers. Chances are, you haven't heard of them. Pretty much the same as Copics Ciaos actually, just cheaper. They come with a brush nib and small broad nibs. I like the fact Deleter packs them in particular sets (gray shades, skin tones, brights, etc.) Extremely helpful, especially if you're not sure what colors you need. Only drawbacks are they are not refillable (as far as I know) and very tough to find. eBay seller "Oozak Online" [link] sells them up to 50% off and ships fast. If you don't have an ebay/paypal account, BlueLine Pro has them, but be aware they sell them full price. [link]
I highly recommend these, especially if you plan to get Copics later on.

Fiber-Castel art markers My personal favorite. I've only recently started using them, but they work wonderfully. (The inking fineliners are very nice also)
Very saturated in color, blend well and dry quickly. Plus they aren't "picky" when it comes to paper like Copics (they're Indian-ink based) and are fade resistant. They also come in sets, but with only 6 markers per set. Unfortunately they are expensive also, not great for shading large areas, not many places carry them and very limited palette; only having up to 48 colors. I found DickBlick.com sells them about 50% off retail price. If you can't get them online, HobbyLobby carries them, but at full price.

As for paper, I highly recommend the "Cartooning Paper" from Hobby Lobby (under the name "Big art Brand"). It's coated (giving it a semi-gloss) and allows for most marker inks to dry relatively quickly and blend well. Even works well with Sharpies and Gel Pens. The drawbacks on it though it's lightweight (causing it to bend easily) and sometimes out-of-stock.
There is also Comic art paper under the "Fan Boy" brand (also sold at Hobby Lobby). Sometimes come in sets (storyboard/cover pages). Pretty good also. They are a tad expensive and you may/may not use some of the pages in said sets.
As for "Copic" paper, don't bother. Just overpriced brand paper. They do work OK, but not enough to justify the price.
Cardstock/Bristol is often used by professionals with the aforementioned marker brands. It works with some people and not with others. In my personal use, Prismas, Sharpies, Fiber-Castells work well on them, not so much Copics/Neopiko.

Feel free to ask additional questions, post tips and such. I don't expect for everyone to agree with my post (and may have pissed off some anime-tards ). Hope this insight will help you.