Crete is one of the largest islands in the med. to assist our members answer your question please give a little more information as to where on crete you are going

wizard

We will be staying in Sissi, but we'll be hiring car while we're there and as it's a special occassion I'd be willing to travel where necessary.

We stay in Sissi a lot and like 'Paradisiako' and 'Fishermans cove' restuarants down in the harbour, tho while you are there you should try them all.
When you get the car (from Gregory at Mevis Cars ) you will probably head over to Agios Nicholiaos, when we go there we stay away from the harbour restuarants (can be quite poor) and always go to 'La Strada' which is up from the lake just before the town centre.
mmmmm! making my mouth water thinking of olive bread and aubergine dip with a gla....bottle of Kritikos local wine

These are my recommendations, I hope to see some more so i can try them also.

Have to agree with "La Strada" in Agios Nikolaos...for Greek/Italian food.Had a few really lovely meals there, beginning of April. Excellent menu...and also really suited me as there were loads of Vegetarian choices.

since the conversation is evolving around Ag. Nik i will express my opinion.
Migomis or Mygomis (not sure of spelling). its above the lake. it is expensive but nice view and good that can be considered good.
La strada is good, but i do not like the fact that its right on the road. for quiet things you have to be inside, and there is no view. Food though is good even though i do not consider it the best i ever had. i do reccomment them though for service etc.
my best one that probably you will not like and sound like not the place for you to go for such day is Portes. small taverna (mezedopolio to be specific) not in the centre of the town but a bit out.
those that go there go for the food. not for the view and not coz its near by the tourism area of the city.