Everyone should go with tier 1 exchanges.This exchanges are safe and secure than any others.But always keep your eyes on their terms and conditions.safest way is to take a note of users feedbacks about them.most feedbacks are genuine so we can trust.
How do you define a tier 1 exchange? If it's determined by volume, then you'll already have some really bad exchanges sitting in the top.
I'm also quite skeptical about user feedbacks. Many of them are either paid promotions or exchange sockpuppets. Large business =/= user safety.