Is there a brand of Geothermal Heat Pumps that stands out above the rest for reliability and reputation?  I am being told Hydron Module is more expensive, but a better heat pump with a better warranty.  Any advice would be appreciated.

Climatemaster, Waterfurnace, FHP, and Hydron are all well made heat pumps. Each manufacturer probably feels that they make the better heat pump.
Hydron's warranty is clearly better than the rest.

In my opinion the best unit is the one the installer or supplier you choose to deal with is going to warranty,feild support, and nurture.  Beyond that they are the same.
I have posted before that I prefer fhp due to their simplicity, and I fish with the regional supplier.  If you fish with the climate master guy, well....

We installed climatemaster, waterfurnace and hydron. For me, each has a slightly different application, and the hydrons cost slightly more. But I am impressed from the HX models, they are just a bit more sturdy made than the others. Many of the components are shared, but some are unique... For hybrid pumps, we like waterfurnace since they seem to have the bugs figured out of their Synergy 3D after 10 years on the market. All 3 brands come now with a 10 year warranty for parts, waterfurnace and hydron with 10 years labor, climatemaster with 5 years labor (upgrade to 10 years for $500). Hydron is the only one with with a lifetime warranty for the original owner for the COMPRESSOR, COAXIAL HEAT EXCHANGER, and STEEL CABINET. And yes, non of them are any good if the installer is not.

Best heat pump is whatever best installer in your area carries. Fishin is an added bonus.
Good Luck,
Joe