I like what you've done here. It is also interesting to note that artists who do particularly well in many categories are known as some of the better rappers.

Andre 3000 paints pictures with his lyrics (word play, ex. Da Art of Storytellin' pt. 1), has a huge variety of spectacular voices and a unique (and amazing) flow for each (delivery, ex. Aquemini), and can rap fast as shit and you can still understand every word if you listen closely (technique, ex. B.O.B.) and this is only one of his many flows.

Nas is probably one of the better story tellers in rap, and you can literally feel the emotion in his words (word play, ex. Undying Love), has one of the best, if not the best flow of any rapper of all time (delivery, ex. NY State of Mind), and may not rap fast all the time but has a unique flow that appears in many of his best tracks (technique, ex. Ether).

Last, somebody who isn't as noteworthy or legendary, but Earl Sweatshirt can literally depress you with his words alone and his beats sure help and frequently uses deep puns that make me want to kill myself (word play, ex. Grief), has a flow that is almost unparalleled (in my opinion) and insanely unique in this day and age of copycat flows (delivery, ex. Assmilk), and is probably one of the best when it comes to rapping in a depressive tone (Technique, ex. Solace).