Tipo 00 - if you can get in!
A favorite of mine. When I was travelling to and working at Melbourne Central a lot, my colleague and I would often dine here early say 5:30pm (easier to get a table) given we'd been awake since 4am having been on the 6am flight.
Sometimes when all the tables are booked they still had bar seating available (its a very small bar).
The current hottest thing is Mercato Centrale. Definitely worth a look.
Went here on the Saturday night of the October long weekend, 3 floors of food options from burgers to pizza to pasta to seafood to cannoli and gelato. It was crazy busy from 6:30 - 8pm, crowds started to think a little from 7:30pm (as those with kids left) and was no drama getting a table from 8pm.
We started on top floor with ok Pizza and wine, then relocated to the bottom floor for the yummiest calamari and an ok lobster roll, and finished on the middle level with ok gelato.
Your order via QR code on the tables (different codes on each level) most places will deliver to your table but you have to pick up the calamari.
For finer dining most of my favourites are Asian fusion like Lucy Liu and Supernaormal. Avoid Serai (over priced and average).
Menu - San Telmo is always nice for Argentinean
Melbourne CBD has IME gotten very expensive in last 12 months.