I have grown Rosemary in pots and in the ground. The Rosemary (Salvia rosmarinus 'Arp') is my favorite because it is so hardy in my location. I use it for cooking and also in my bath. I also plant it just for the wonderful scent. I prefer to plant it in ground because it has a better survival rate for me. I can just plant it and forget it (as far as maintenance goes).
This plant is 5 or 6 years old and very woody but it still provides lots of rosemary leaves for cooking, etc... I usually cut stems to use whole in my cooking.