I can vouch that I shop on Victorias Secret.com at least twice a month. They always have items on sale, a wide variety of colors to choose from, they offer a great choice in clothing (yes, clothes, not just undergarments) and their return process is easy and efficient. There sizes are sometimes hard to master. Undergarments are accurate to your normal size, but I would go up one size in clothes, esp. pants, b/c they are often slim cut. Overall I love this website and their level of customer service, with lots of "angel rewards" varying from gift cards, discounts or promos.
I am an avid fan of both Nordstroms and Nordstroms.com. EVERY TIME I have an event to attend by first stop is Nordstroms.com. There is always a sale worth browsing, their shipping in only $5.00, their sizes are accurate, and if you happen to need to return you item for whatever reason, you can simply send it back, with the provided, pre-paid postage, OR take it to the store,no questions asked.