The top two (PCGS and NGC) require membership for grading submissions. Costs and benefits are listed on their websites. ANACS and Dominion Grading Service (formerly ICG) accept direct submissions and again fees are listed on their websites. These are the only grading services I would personally recommend.
An alternative to PCGS/NGC membership is submission through an authorized dealer. Check your local coin shops to see if they are PCGS or NGC members and if they will accept your coins for submission. They will set a fee structure for this service.
I assume you want these graded and slabbed to sell. Grading service confidence has a lot to do with liquidity. PCGS graded and slabbed coins enjoy the highest resale prices and move the fastest. Followed by NGC and ANACS. DGS is brand new and the jury is still out, but initial examples of their product appear to reflect stringent grading standards.
Hope this helps.
