Humminbirds read Lakemaster and Navionics digital mapping.
The "best" for you is the one that has the coverage you want, where you want, how you want it.
You can view the current maps that Navionics has on their website's Web App.
You can download the lakelist that Lakemaster has on the Humminbird Lakemaster website.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1