Just like the old saying - Fast, Good, and Cheap. Pick two.
Fast & Good - Ryan (InTime.co). I haven't dealt with him, but people rave about his fantastic service and speedy DHL shipping. Prices seem higher.
Fast & Cheap - Sead (SuperMirrors). It may seem mean to exclude "good" from his description, but he's my primary dealer. He has fast communication and shipping, his prices are usually 10% cheaper than others via paypal, and once in awhile he throws in free shipping if you buy tons from him. While I trust his own QC, he rarely provides QC pictures for the buyer and his replies are very short and incomplete. Great dealer for bargain hunters.
Cheap & Good -Angus (Puretime). Cheap with his 10% WU discount and 5% promo codes, his site seems to be the one everyone bases their prices on. Great QC pictures and payment options. Slow communication and I've had to wait up to a month for a watch I was told was in stock.
A bit of all three (but excelling at none?) - ToroBravos. He's had some hiccups but he tries to do all 3 with 10% WU Discounts, Special Prices, good QC, and fast correspondence. I've had minor problems that made me switch TDs, but I'm not opposed to trying again.