Out for Justice - best bar scene, best reality self-defense in the very last scene of the film. Overall, I think this is the best Seagal film, partially because of the villain and partially because of, well... its actually entertaining.
Undersiege 2 - uh, best one-liner. At least it's better than "I'll take you to the bank, senator. A BLOOD BANK."
Also features a big-breasted acting school reject as Seagal's niece, who uses a nikkyo, and a comic-relief black guy who learns the said nikkyo after having it applied on him once, and later on, of course, he applies it successfully on a highly trained mercenary.
Above the Law - some dojo scenes in the beginning, baseball bat fighting, a guy gets his hand cut off by a knife which was held by another guy who was kotegaeshi'ed.
Excellent store fight sequence.
The film has absolutely no value as a standalone film, however.
Undersiege 1 - probably worst Seagal film I've seen so far.
Exit Wounds - the first film with Seagal using wirework, has a nice bar scene where a giant bouncer forces himself out of an ikkyo.
Hard To Kill - good premise, and Kelly Lebrock is pretty. Cough. There's a good store fight sequence in the beginning, and an in-house fight sequence in the middle, featuring people flung off balconies, knives, shotguns and broken limbs.
Has Seagal's worst ever one-liner (see above).