TV-viewer
beholder
bird-watcher
bystander
drugstore cowboy
eyewitness
gaper
gazer
gazer-on
girl-watcher
goggler
kibitzer
looker
looker-on
observer
ogler
onlooker
perceiver
percipient
seer
sidewalk superintendent
spectator
spectatress
spectatrix
television-viewer
video-gazer
viewer
watcher
witness