I have installed installed JEvents and find it clumsy and laborious when entering events, not to mention the un-professional presentation.
JCalPro looks great and is much easier to use.
GCalendar doesn't allow a print option, and lacks a lot of features. If you want a basic calendar, then it will probably fit your needs.
The RSVP module that is bundled with JCalPro does not integrate with JCalPro, and is almost identical to Attend Events in functionality.