Additionally you don't "NEED" css to be search engine friendly. You need proper use of content, code, and meta data, and link backs don't hurt either.
Of course you don't NEED css to be search engine friendly. You do NEED proper
use of content, code and meta data, plus revelant back links. An awful lot depends on the complexity of your site, it's functionality and purpose - as to rather HTML alone is the answer. More often than not, CSS/HTML is the better fit.
And congrats on the success of your non-css site, ANMark.