Should I Switch out my Veneers for Crowns?

After reading your question, it seems to me that your veneers are breaking due to an underlying "bite" problem.  Veneers are great restorations, but when placed into a destructive bite are prone to fracturing.  Do you grind your teeth at night? If the answer is yes, then you must wear a night guard to protect the porcelain.  Do you have a severe overbite?  Significant overbites can be tough on veneers if they are not placed out of the way of where the majority of your chewing forces occur. You should consult with a dentist that does lots of cosmetic dentistry and let them determine if you would be better suited with crowns. 

Veneers coming of can be a common occurance in a dental office that is new to smile makeovers or simply lacks the skills or experience.  A lot of factors go into a successful veneer case, including material selected (type of porcelain or resin), bonding agent ("glue") and the bite.  If your occlusion (bite) is parafunctional, veneers will pop off or break.  It is possible that an equilibrated, or balanced, bite will help.

Replacing veneers with crowns is certainly an option, but I would save it for last.

In your specific case of veneers regularly breaking or popping off sounds like a bite or Occlusal problem or perhaps a preparation and or bonding problem. Either way, before your case is redone your bite should be carefully evaluated for parafunctional habits or too much stress placed on your front teeth during function. If Occlusal problems are present it may be in your best interest to change your approach to Full coverage Porcelain crowns. Even before this approach is considered  Occlusal adjustments and an appliance to protect you from clenching may be a great place to start before future permanent Crowns or Veneers are placed. If you decide to have Crowns placed i agree with another post here in this forum regarding Emax all Porcelain crowns. They have excellent strength as well as superior Esthetic properties to match!