I've been searching for airfare from Naples to Lanzarote,
Spain but am getting crazy airfares (ie $900 and up). The best so far is from Naples to Lanzarote via London on British Airways for $225 but I arrive in London 9pm and leave the following morning at 8am. Does anybody know of a good website to go to other than Orbitz, Expedia, etc? Alitalia doesn't fly to Lanzarote.

Try one of the budget airlines, but you will probably have to connect in Germany/UK or somwhere.
www.whichbudget.com

I think you're best bet will be to try the low cost airlines from Naples to Germany/UK/Spain and then transfer to Lanzarote or trying if you can have a direct flight to Gran Canaria (Las Palmas) and from there is a short and cheap flight to Lanzarote.

Try Transavia.com.
They are a low cost Dutch airline and they fly to both Naples and Lanzarote via Amsterdam

Really try to do it via Spain or from Italy to the Canary Islands (any Island), from Amsterdam or London to Lanzarote it's an almost 6 hours flight, from Spain it's about 3 and a half.