The key to a thriller is subtlety - and these films don't have it; Excesses spoil 'Terror,' 'Crimes,' and 'Thief'

The title of ''Terror in the Aisles'' puzzles me. I usually stay in my seat while watching a movie, and the movie usually stays on the screen. So what's going on in the aisles?

Eager to find out, I hurried to see ''Terror in the Aisles'' and kept one eye on the aisle to my left. I saw nothing terrifying, though. Maybe the terror was in another aisle. Or in the balcony. Or maybe they leave out the terror at press screenings, since critics can't type reviews while trembling.

But there was plenty of terror on the screen. A product of Universal Pictures , long associated with superior horror movies, ''Terror in the Aisles'' is an aggressively awful collection of fright-film highlights. A few come from classics like the original ''Dracula'' and ''Frankenstein,'' which are relatively tame. Most are from modern thrillers, however, complete with yucky effects and R-rated explicitness.

Since there's no story, just a parade of gory climaxes, credit for the movie's impact goes less to director Andrew J. Kuehn than to editor Gregory McClatchy, who keeps the pace and the images hopping, at least when the dopey narration by Nancy Allen and Donald Pleasence doesn't get in the way. For students of the genre, there's a ghoulish pleasure in watching scenes from almost 75 thrillers do a feature-length danse macabre. But there are sobering undercurrents, too, as clip after clip illustrates the shameless victimization of women, which is a sad constant in the horror field. 'Crimes of Passion'

Speaking of horror, the irrepressible Ken Russell serves up a walloping dose in ''Crimes of Passion,'' his latest exercise in excess. The main character (Kathleen Turner) is a fashion designer by day, a prostitute by night. Into her life comes a clean-cut fellow whose middle-class marriage is falling apart. Onto her trail comes a crazed clergyman (Anthony Perkins), who's determined to save her soul by murderous means.

As often happens in a Russell movie, the plot is just an excuse for zany flights of fancy, splashed across the screen with the most wild-eyed visual style this side of the psychedelic '60s. Russell is probably today's only Hollywood director nervy enough to put a blinking neon sign outside the heroine's hotel room and shoot whole scenes in flashes of garish light and utter darkness. The actors join in with gusto, playing their uproariously squalid roles to the hilt, and Perkins caps the insanity with a lurid parody on his famous ''Psycho'' character. I'm sure there's a slot reserved for this hodgepodge in the future ''midnight movie'' scene. Meanwhile, approach with extreme caution. 'Thief of Hearts'

''Thief of Hearts'' is more restrained but not more sensible. The plot chugs into motion when a young burglar steals a woman's diary. After reading her secrets and fantasies, he barges into her life, seducing her and shaking up her marriage with his ill-gotten insights into her most private thoughts.

This isn't the first movie about an outsider who launches a psychological invasion into the ''respectable'' world. Antecedents for ''Thief of Hearts'' include ''American Gigolo'' and ''The Shout,'' as well as ''Knife in the Water, '' which gets a brief homage in one scene.

But director Douglas Day Stewart lets prosaic mannerisms intrude on the action - prettified shots of sky and water, tough-guy cliches, a grating rock-music score. The screenplay is often pretentious, and the climax is so strung out it loses any suspense it might have had. Less is more in the thriller format, especially when the thriller wants to be thoughtful. ''Thief of Hearts'' would work better if it didn't try so hard.