Jeans: Levi's 511, 514, 513, or 508 in a dark, undistressed wash. 511 is a slim cut; if your thighs are bigger go with the 514. 514 doesn't taped from knee to leg like I prefer, so the 513/508 is the same cut but tapered below the knee for a smaller leg opening. Other than Levi's the only jeans I really like are selvedge; we could do another thread on selvedge denim alone, as the material/process/theory behind it is pretty different, and most people find the idea of wearing jeans for 8 months without washing them a bit extreme.
Chinos: Dockers D1. If your ass/theighs don't fit then go D2 but I'd rather size up in D1 than switch to D2 in the same size; the cut is just far better. Stick with colors like grey, charcoal, navy, khaki, buckskin, and olive.
T-shirts: Target's house brand Mossimo makes the absolute best fitting and quality crew and v-neck shirts for the money as far as I'm concerned ($10 each). 90% of the time I'd say a V-neck looks better than a crew neck, and I'd stick to natural, heathered colors (grey, charcoal, navy, brown, maroon, lavender, etc). On t-shirts black/white is generally fine, but people generally think they're more neutral than they are (charcoal is way more versatile/neutral than black, for instance).
Shirts: Dress shirts are another story, but casual button-ups and OCBD's (oxford cloth button down, it's a really specific fabric) are literally all about fit (technically everything should be fit-focused, but button-ups/downs are the easiest to fuck up). Target's Merona has some great OCBD's and a few gingham/bengal stripe and solid colored shirts that fit most frames pretty well. I'm a big fan of JCrew's specific cut, and Uniqlo (when they're in stock) is insane bang-for-buck. JCPenney's spring line is also really leaps and bounds ahead of what they used to offer; their shirts and even blazers look pretty awesome this season, but that's no surprise considering Nick Wooster was the guy behind it.
I'd read the sidebar over at
http://www.reddit.com/r/malefashionadvice when you get some time to sit down with it - they go into more detail explaining the reasoning behind these choices. They also do multiple WAYWT and outfit/fit check threads every week; if you're seriously interested in dressing better it's a great resource and I'm constantly saving pictures to specific folders as inspiration for different styles, seasons, color schemes, 'themes,' etc.
