My favourite "authentic" Mexican is Los Amates on Johnston St, between Brunswick & Nicholson Sts.
http://www.losamates.com.au/
Also on Johnston, on the same side but across Brunswick, is Shocolate, a magnificent Chocolate dessert cafe.
http://www.frenchmancuisine.com/2011/02/sublime-macarons-shocolate-master.html
As for Indian, the Tandoori Den, almost on Camberwell Junction, is consistently the best over 20 years.
http://www.tandooriden.com.au
My favourite food is French, but I have found it hard to locate a great French restaurant.
I loved Jean Jacques in North Melbourne, 25 years ago.
Also, I loved the French restaurants hosted by Emil & Marie on the Gold Coast, Qld, over many decades.
Emile passed away many years ago; of Marie's whereabouts, I'm not sure.
My favourite breakfast spot is Bumbles Cafe, on Bumbles Beach, behind Surfers, on the Gold Coast, hosted by the great and amazing Kate Madison, who I've counted as a close friend for nigh 30 years.
http://www.bumblescafe.com/
Of dining spots, few beat Fremantle Wharf, where you can stay at the Esplanade, and dine at the Little Creatures Brewery, Cicerellos restaurant, or the fresh seafood market.
https://littlecreatures.com.au/find-us
http://www.cicerellos.com.au/
I used to really enjoy the old Moore's restaurant in Sandy Bay, 25 years ago. The current one is good, but not as.
There is also a fantastic small restaurant in Launceston whose name escapes me. It has been some while.
Stillwater is also very good.