Over the years of living in Florida, I have grown and fruited the following Annonas...
Guanabana (Mario1)
Atemoya (Gefner)
Sugar apple (Big Green)
Sugar apple (Big Red)
Sugar apple (Kampong Mauve)
Sugar apple (Cuban seedless)
Ilama (Genova Red)
Rollinia (Amazon Beauty)
Custard Apple (Canul)
I have tasted most of of the other annonas grown in Florida at one time or another. To my Caribbean-biased taste buds, the best tasting Annonas are the Genova Red Ilama which tastes like a creamy sweet raspberry atemoya with zero grit.....The Big Red sugar apple...I sell lots of these and most people that buy them are annona fanatics from sugar apple havens like India, Jamaica and Cuba and the majority of them say it's the best sugar apple they have ever tried. They are bigger and tastier than the Red Mauve and much more prolific. Perfectly ripened Gefner Atemoyas are also incredible. The sweet Guanabanas that Oscar mentioned are also awesome. I tried one in Puerto Rico that was as sweet as a sugar apple! Top notch Rollinias are also very excellent but the quality of fruits is sporadic. I have also tasted the best PawPaw cultivars from Ohio and would rate them at the low end of the spectrum. They all have an aftertaste that does not agree with me.
Regarding Cherimoyas, I have also been to California several times and have tasted tree ripened Cherimoyas that were grown in Santa Barbara, Simi Valley and Camarillo. The ones I tasted included Booth, Ott, El Bumpo, White, Pierce and several others that I can't remember. The best ones I tried were very nice but in my opinion, not as good as the previously mentioned Annonas. I did not grow up eating annonas, it was a learned behavior. Not to upset the California folks, you guys can grow a delicious Cherimoya, but you need a try a perfectly ripened sugar apple which is very difficult to find in the mainland US outside of South Florida. The area where I live in Broward County Florida very likely has among the best overall climatic & soil conditions for Sugar apples and Atemoyas on the mainland.
The key to any of these Annonas is eating fruits that are perfectly ripened in the place where they grow the best. Florida grown Cherimoyas, are plain mediocre. We do not have the proper growing conditions that Camarillo Calif has. I would think that sugar apples that fruit in California will not as good since they require high humidity and they don't do as well in the cooler climate. To finish this off, those of you that have not tasted a perfectly ripened Genova Red Ilama or a Big Red sugar apple need to add these to your bucket list! Just my humble opinion !!!!
Genova Red Ilama
Big Red Sugar Apple