I joke around with my gf that I've been seeing two women on the side in my frequent trips to beijing over the past four years, Alice and Wendy (both on the 3rd floor of Ya Xiu market in sanlitun).

I second the post above that Wendy Tailor is pretty quality in terms of suits. Shirt fabric selection is not as strong as others. They tend to haggle for higher prices than others, despite being a repeat customer. But the suits have been pretty good quality.

On the shirts route, I have almost exclusively stuck with Alice My Tailor (aside from a couple escapades with Wendy), since I have always been pleased and the fabric selection is pretty good. Last week, I returned to them for two suits. I am very pleased with the results. However, I only gave them the bare minimum of time (3 days) and they forgot to sew a couple of button holes, which I'll now have to have added by a tailor in the US. I also had them copy a women's shirt on a couple occasions and the fit has been perfect. Shirts have now increased from 100 to 120rmb (non-negotiable as far as I can tell, and since they don't give you BS highball initial quotes like some other vendors in the market, I'm cool with it). Suits I bargained down to 800rmb x 2 suits (though they always want to charge me slightly more for fabric for my size). Initial quote was 1200rmb for one. I got a reasonable discount for buying a ton of shirts too I believe. It can also help to wear one of their shirts into the shop to show you're a repeat customer and also serve as a guide to get the measurements.

I also think the time of year matters in terms of schedule and price. You can get quicker turnaround time in the non-summer seasons, and perhaps bargain for better prices. Definitely avoid Chinese New Year. The tailoring staff are likely migrant workers and head home to their villages for about a month at that time (late Jan or early Feb).

In general, the quality of fabric and tailoring may not match the best tailors of HK (or beijing or shanghai for that matter), but they'll last you a handful of years and for the price you can't argue too much.

My main beef is they put a stupid tag on the suit that says nothing but an email address. Looks kinda cheap and odd. I keep forgetting to request something else.