Synonyms for Unexceptional:

adj.

acceptable (adjective)
standard.
all right (adjective)
good.
average (adjective)
run-of-the-mill, ordinary.
commonplace (adjective)
mundane.
everyday (adjective)
stock.
mediocre (adjective)
indifferent.
unexceptional (adjective)
routine, commonplace, average, undistinguished, garden-variety, usual, plain, mediocre, run-of-the-mill, unremarkable, common.

n.

mediocre, average, undistinguished, formulaic, stock, indifferent, good, cut-and-dried, routine, nondescript, standard, unremarkable, commonplace, mundane, garden-variety, plain, usual, garden, common. unexceptional (noun)
run-of-the-mill, run-of-the-mine, ordinary.

Other synonyms:

nondescript, garden-variety, unremarkable, formulaic, cut-and-dried. mundane, undistinguished, routine, mediocre, garden. commonplace. average. indifferent. plain. common. Other relevant words:
mediocre, average, undistinguished, formulaic, stock, indifferent, good, cut-and-dried, routine, nondescript, standard, unremarkable, commonplace, mundane, garden-variety, plain, usual, garden, common.