@Sephora offers some of the top and best quality nail polish available and has a huge variety. Other options could be @Boots which offers drugstore makeup branded nail polishes

Where can I find teeth whitening strips?

At any pharmacy like @BinSina Pharmacy or @Boots

Where can I find the best bronzer?

@Boots or @Carrefour offer an awesome range of drugstore make up products, like bronzers, so you should definitely check them out if you're looking for the not so high end make up branded products

Where can I find gel eyeliner?

Hands down the best gel eyeliner there is out there is from @Bobbi Brown as said by multiple beauty gurus, also a great dupe for it could be the Maybelline gel eyeliner which is sold at places like @Boots or @Spinneys @Carrefour

Where can I purchase leading beauty and makeup products?

@Boots is another great one to check out in Dubai, not offering a lot of variety but definitely selling a good amount of drug store beauty and makeup products like Revlon, Rimmel London and Maybeline being a few of the brands

Where can I find the best skin care products?

@Boots !