Daily Deal sites (like Groupon), which do you like? What made you like / trust them?

[Ember]

I have just moved to Australia, and there are a whole bunch of daily deals sites, so I'd like to try. Back in North America, I used Groupon and LivingSocial. There were others, I just never tried them. My question is, for those who have used sites like these, did you do any background checking first? If so, where did you look? Also, have you ever encountered any problems with these sites?