About Polycount

This is about polycount of Sims 2 objects. I'm one of the few creators, who name polycounts of their meshes. I do it for those, who need to have a look at polycount, because some computers can't handle highly detailed objects. In the beginnings of creating CC for Sims 2, it had to be lower poly, because computer technologie wasn't advanced enough for games like you can purchase today. Of course, I could offer low poly stuff, but who would want that, when your PC could easily deal with premium quality? I try to keep polycount on a reasonable level; if it's high, I spread it on several tiles and I'm almost sure, that none of my meshes will crash your game, no matter how poor your machine may be.
The following is quoted from Jonesi @ Blackpearlsims:

For objects, Maxis gave us a guideline of around 800 polys per tile, but that's a very fuzzy guideline that they exceed themselves on numerous occasions. It has to be balanced based on the detail and usefulness of the object - a very simple boxy sofa probably shouldn't be 800 polys per tile, but a very fancy one could push higher than that and be just fine.
For an item you would use over and over on a lot - like a dining room chair, you would want as low a count as possible. For a very decorative item you would only use once, you could go a little higher. The upper limit for objects is around 2000 polys per tile - it'd have to be very special to be much higher.
For body meshes, anywhere from around 1600-2500 is within expected normal ranges. Higher than that, the mesh would need to have a lot of necessary detail to warrant a higher count... Alpha meshes can often push higher. The upper limit for everyday use would be around 3000 polys for clothing/bodies (that's a full body, not separates).
For extremely special items like runway fashion, you can go higher - you'd only use them once per lot, and rarely. The Atlaua peacock dress is somewhere around 12-15k polys, which is extremely high, but the level of detail is warranted, and one would likely never put that on more than one sim at once.
For hair, Maxis meshes range from around 500 polys for really simple short male hair to about 3000 for more complicated female updos with funky stuff on them. Most everyday-use hair should range from 1000-2000 polys, with extra-detailed, curly, or special hair going up to about 3000 polys. Hair would have to be -very- special and used very rarely to push much higher, the upper limit being around 5000 for something incredibly special and complex in shape.
For accessories, it really varies, but probably about the same as hair in terms of ranges for usability. 
The rule of thumb to keep in mind is no more than 1200 polys per sim square. The more detailed an item the more polys it will have.