I recently switched to GO Launcher and lost the stock HTC Calendar widget, so I went off to find a replacement. I found Business Calendar Beta
, and it does everything I need it to do. Syncs with Google calendars. The widget displays a month view with calendar entries as either bars or text. You can configure the widget so that tapping a day takes you straight to that day in the calendar app. Tapping a day in the app shows a pop-up with the details of that day.
Overall it's a really, really nice calendar app, and best of all it's FREE.