If we're talking about "business casual" attire, I find the Banana Republic "Dawson Fit" Chinos spot on. It's leg openings offers an excellent compromise -- not too flarish yet not too tapered. Though it's a bit larger than standard "straight cut", I find it to be very convenient since it "goes over" my shoelaces. I know this brand is somewhat highend but it's the only one with the "cut" that suits me well so if anyone has violent reactions...
For long sleeved dress or short sleeved button down shirts(for hot days), I usually don't buy into the "branded mentality syndrome" but look for a practical alternative instead. I'd rather get a relatively well made, 100% cotton, employs not too "cheaply" thin materials and are made by a respectable company/brand.
For shoes, I put more emphasis on function but aren't too "de-fuglying" on form. I prefer the lace up, plain-toe oxfords or slip-on loafers that are simple in design yet exudes some "bad arse-ness". For the function, I usually do my homework first on which ones have the best technology for cushioning, comfort, walkability, etc. then go out and try them to see which ones live up to their claims. Something I discovered is that while many of the higher-end, classier brands have the best materials(Italian leather) and build quality(handmade), they tend to be lacking in the technology department for cushioning, comfort, walkability, etc.
For belts, I always buy a nice branded one because I consider this a good long-term investment. Also, good ones tend to last much more than those ubitiquous cheap ones you find just about everywhere.
Lastly, for those really serious into "dressing right", check out
Askmen.com. Just do a search, it has buckloads and truckloads of information regarding this topic. Their top babes rankings doesn't hurt either.

Cheers!