This is actually my favourite cafe in Melbourne! They do delicious south american aprea's with various fillings (i recommend the breakfast one) which goes perfectly with their consistently good long blacks.
A true underrated gem, old school style italian coffee - no frills or fancy latte art but just really good and strong italian espresso. They also do a huge and cheap variety of made to order sandwiches
Sila Espresso Bar Fitzroy
Collingwood
For coffee purists - they only do black coffee, no milk allowed!