Hill O'Chips is probably the most original. Second is probably "The Boulevard". That's its official and complete name.
Less original, but not very common in Canada at least, is that our downtown cross streets are mostly coves - Bishop's Cove, Beck's Cove, Ayre's Cove, Clift's-Baird's Cove, and Job's Cove. We never used to have a street along the harbour, just cross streets ending directly at it, so they were coves before Harbour Drive was constructed.
Also less original, but equally uncommon in Canada, as the Royal Newfoundland Regiment fought in Africa, the Middle East, and Turkey during WWII, there are a lot of streets named for battles that loom large here but aren't really discussed in Canada. The Dardanelles, Malta Street, Cairo Street, Suvla Street, Suez Street, etc. If not for the connotation, The Dardanelles is a pretty street name.
In terms of just pretty ones... I like Bonaventure Avenue. The main drag through my neighbourhood is cute too, Merrymeeting Road. Carpasian Road sounds nice (the reference is Cyprus, WWII related again).