Some article sites give you plenty of details about the articles you're getting, telling you the topics available and showing you examples.

Mike Long has managed to sell almost all his membership spots without revealing such details - and he's done so very quickly.

However, I can tell you that topics covered in his November batch are product oriented. They cover:

Coffee
Sports Jerseys
Satellite TV & Radio
Contact Lenses
Baseball Equipment Cell Phones & Accessories
Golf Equipment
Poker Chips & Supplies
Fishing Equipment
Laptops
plus a bonus
Each month he'll provide 250 articles across 10 different niches. I'm a member of his site. The articles are well written. Fantastic value.

Because Mike's site has been very popular, I'm not sure if any membership spots will be left by the time you read this.

[UPDATE 2008: Mike has stopped providing this service.]

What other article sites do you belong to?

I belong to these good sites...

Nicheology, launched last year by Jimmy D. Brown and Ryan Deiss, quickly reached its membership cap of 1,500 members. New memberships are offered when an existing member leaves. The site provides lots of details, instructions and a forum for members. This is a very professional site. You can put your name down on a waiting list. I belong to this one and recommend it.
http://www.AssociatePrograms.com/niche-articles

Stefan Everaet provides at least 60 very high quality articles each month, plus superb graphics and keyword research. Stefan says that this month, the three main topics will cover weddings, web hosting and wine. Upgrades for his credit cards and cats packages will be released, too. He provides not just articles but complete niche content packages. See the details on the site. Only 67 membership spots are left.

Stefan provides very high quality articles. I recommend this site. It's excellent value.

Full details here:
http://www.niche-content-packages.com
Get a discount by using this link:
http://www.niche-content-packages.com/allangardyne.htm

Kim Standerline covers in-demand health topics. Each month, she provides two complete health niche products written by a registered nurse, another 25 private label articles, keywords research for each niche, a private forum, bonuses, and all sorts of useful assistance. Check out all the details on the site. If you're interested in health, you'll love this service.
http://www.AssociatePrograms.com/health

Here's an article site which I haven't tried. It looks promising...

Bryan Winters provides a huge article database. Members get unlimited access to over 40 niche categories and hundreds of topics. You also have access to niche content article packs and private label products with the sales letters already written for you. You can post "articles wanted" requests. If you like writing articles, you can get paid for them. There is no restriction on membership numbers. The membership fee is modest.
http://www.AssociatePrograms.com/bryan