Choosing which beauty box to subscribe to is HARD. Really hard, essentially your putting your faith in a company to give you a good return on £10-£13 a month for 5-6 product samples. I'm always asked which beauty box I'd recommend, and I can't honestly answer that question. Seeing as contents vary from month to month there is no real way of me saying "this service is better than this one" as every month the samples are different, its all down to personal preference and your taste.
One month could be an amazing beauty box the next could be a terrible one, They are incredibly unpredictable. However one persons rubbish is another ones treasure. For example I know I don't like Carmine, I got the first box, thought it wasn't for me and unsubscribed, I then resubscribed and got another two boxes which I didn't like (I didnt even post about them so it says alot!). So Carmine has beens eliminated for me. However I know a lot of people love Carmine as they tend to give out make up samples (which I don't want).
At the end of the day your the only one that can decide which box you feel is right for you. The more I think about it the more I realise beauty boxes are a bit of a waste of money. Especially if you cant afford to waste money each month on things you might not like. Sometimes I think I should have spent that tenner on one product I wanted rather than 5 that I probably wont use. I see alot of people commenting on the beauty box Facebook pages requesting Nars or MAC stuff in their boxes, but you have to realise that beauty boxes aren't an excuse to stock up on high end products. They are samples for you to try and see if you like. Beauty boxes aren't trying to give you products for cheap, they are giving you a sample in the hope that you'd like it and go on to buy full size. Would you rather have a full size MAC eye-shadow (£12 or £10 if you wanted one in a pan!) that you know you'll love because you picked it yourself or risk that money on 5 you might not?
I don't think beauty boxes are for everybody. I subscribe to (and pay for) Feel Unique and then get Glossy Box and Jolie Box sent for free for me to review. I know for a fact that if I wasn't getting the two free I wouldn't be paying for all three. That'd be over £30 a month I'd be essentially gambling away. I wouldn't personally recommend subscribing to more than one box. I do know that if it came down to only choosing one box, I wouldn't know which I'd choose to keep. Its worth checking through reviews to get a "feel" for the types of brands and contents each beauty box service puts in. But in reality there really is no way for me to say which is the best, or which one might be right for you.
Would be great if you could leave in the comments which box (if any) you subscribe to and why you personally picked that box!