Macroalgae can be really gorgeous, especially the red imo
. The dragon's breath is my favorite, but I have yet to buy some. I really like the Eucheuma Spinosum (red) portieria sp. (more orangish) and the red grape. I have a lot of different types and the marine plants that require calcium (like the H. Opuntia & C. Barbata) aren't as hardy in my experiences. Any type of caulerpa can take over fast so be aware. I got all my plants at live-plants.com. They have great portions for the price. Much cheaper than anywhere else I've found.