Final answer:
The correctly punctuated sentences are 'The Sunbeam Shop (our new bakery) sells delicious eclairs' and 'David's favorite book is Great Expectations, but my favorite book is A Tale of Two Cities'.
Step-by-step explanation:
The sentence punctuated correctly among the options provided is: 
The Sunbeam Shop (our new bakery) sells delicious eclairs. 
This sentence uses parentheses to add a non-essential clause, which is the correct punctuation in this context. For the other set of sentences, the correct punctuation would be: 
David's favorite book is Great Expectations, but my favorite book is A Tale of Two Cities. T
his sentence correctly uses a comma before the coordinating conjunction 'but' to connect two independent clauses.