The client-side story of XMPP is pretty bleak, especially if you're trying to get non-technical people to use it.
Over the past years I used 'Pidgin' as my desktop client, but it was not were I wanted it to be so I was actively looking for alternatives. Dino looked very promising on paper (supported XEPs) but they lack basic stuff like systray support (at least the last time I checked it out).
For a long time Gajim wasn't any better than Pidgin, but earlier this year they released their version 1.0 which added support for some more XEPs most importantly MAM (enables proper history synchronization between clients). Since that release I switched to Gajim and stopped looking for alternatives ;-)