I have tried AliExpress, DHGate and some similar sites. AliExpress is hands down the best. I have been using them about 2 years now and I've made roughly 35 orders.
I've bought two formal dresses on the site for much lower costs than anything local. The quality was still great, esp. When I see "Made in China" on all the local shop tags. You are getting the same products for way less! The only caveat for buying clothes is to READ THE MEASUREMENTS. Remember, these are typically sized for Asian bodies, so if you are a US size L, you may need an XXL. Some stores do size in US sizes, or they list as "Plus" size, which is more like size M-L for US, but it's not hard to find many options once you learn the keywords to search.
I've bought cute tote bags for my mom and grandma, adorable best friend necklaces, galaxy pendants, some cute funky looking sweaters... very cool gift ideas and many things I hadn't seen here in the US, so it makes my gifts more unique.
If you're buying for an event, make sure you buy in advanced. Shipping can take up to 6 weeks sometimes, but I think it's worth the low price.
I've had 2 disputes in the past and AliExpress resolved them quickly. In once case I bought 3 pairs of tights and 1 pair was too small and long. I took a photo of all 3 side by side to show they weren't the same size, and they ended up giving me a refund for that one pair but let me keep. So I gave those to my sister who is petite sized.
Also, AliExpress cancelled an order once when they suspected the buyer was a scam. So I appreciate that they look out for you. I always suggest this site to friends.