First off a big Thank You and Congrats on even thinking about getting designations and certifications you are steps ahead of the average agent just for giving it some thought.
 
GRI, is a great place to start, most you covered in your classes to get your license but this time it's more intense and to the point on how to be successful.

E-pro, is essential to learn how to navagate the web, I have picked up several buyers because of the sites I found out about in the course
 
CRS, is the #1 to me, you become one of the very best in the industry because of the strict requirements. As a CRS Realtor you have a constant flow of information available to you that others do not have easy access to, a referral base second to none. This year I have referred to 5 members located in California, Miami, Denver, Arizona and Dallas. By the way I only refer to agents that have at least 3 designations, I want my clients to be well taken care of and have found that those who continue to take classes beyond what is required tend to care more about their clients as well.
 
Green is the wave of the future and I enjoyed the class very much, we all need to think Green it's not going away.  Few have this designation right now so you would be amoung the first.

CNE, Certified Negotiation Expert, is one of the few classes that teaches Selling Skills, if you have not been in sales before this is one class I highly recommend, if you have it's a great way to refresh your skills.

ABR, is quick and most clients recognize it so it can be very useful.

CIPS,  what a wonderful experience, if you are thinking of working out of the country or just want to understand how real estate transactions are handled in other countries this is the course for you, I enjoyed it very much,

I also reccomend you get acctive in your local Association, join committees, I have learned much from other members in these meeting that I have been able to put to good use and it doesn't cost a dime. Sign up for the Leadership Program , I was in the First leadership group here in Houston and gained true friendships with Realtors from all over the area and now have a great source for imformation when ever something comes up, talk about Priceless. 

It all depends on you and where you want to take your career, designations are impressive, I get many comments on the number I have acheived, just shows that I care about knowing all there is to know about this business. It was my personal choice and I have no regrets.

Wishing you much success and joy as a Realtor