As of right now, I have over 130 orders (most of them for me, but a few for a friend who doesn't have a credit card) from AliExpress over the last two years.
I've had nothing but positive experience with them. A couple of items got lost in the mail (tee strainer, knockoff Thinking Putty, tiny aluminum pill bottle) but I got a refund on those immediately. I've bought over 15 phone cases and none were more than $2 with free shipping. I honestly cannot recommend AliExpress enough.
What I would steer clear off are clothes. Never buy clothes! Not only are the sizes always 2 or 3 sizes smaller than they claim, the fabric is always super cheap and unpleasant to wear.
As far as sex toys go, I've bought one butt plug
and the quality is amazing. Far better than the $50 Doc Johnson dildo that I bought from some legit adult website.
The only issue with AliExpress is, the shipping takes forever. Literally. I've had some luck when I got my items in 2-3 weeks, but on average I wait at least 5-6 weeks, pretty sure I waited almost 3 months once as well. But since shipping is free (I only pick free shipping) I'm not gonna complain about that.