Specifically there are a few things I like from Picasa:
1. Import files to folder based on picture dates
e.g.: c:\pictures\2016-02-12\P0221314.jpg
2. Import videos from mobile devices and display in the right orientation
for example: I have mobile devices and I take movies in different orientation: vertical or horizontal, while the actual file's metadata is left unchanged, Picasa knows the _right_ orientation and will adjust the playback accordingly.
3. Handles upload from different devices
I have a Lumix GF1 and iPod. Importing pictures to Picasa is super easy without any 3rd-party integration/interruption (e.g.: doesn't have to copy from device to a temporary folder first but instead import directly from the device to the dated folder).