I agree with the others that Tim Finn is great, as is Before and After. Imaginary Kingdom is a strong album too. If you're not necessarily wanting to be completest to begin with, how about the anthology? While some of the songs are reworked (and CH/Enz), there's something of a selection across his solo albums save the most recent one (if memory serves), so that might give you a taste and help determine if there's an era that you like, since they're all quite different. Or, if you're a completest, why not start at the beginning with Escapade?
Completely agree with this. Tim’s albums are quite eclectic based on the era they were produced. I love many of the songs on Big Canoe but the production... well... is an acquired taste! I feel the same about Escapade.
I would also either start at the beginning and make your way through them all or start with the Anthology and explore the albums based on the songs that most take your fancy.