Minor innacuracy is ok, especially with 'hard to find' or inaccessable equipment...
Example: You can't expect Paramount to come up with MiG-25s or 29s for 'Top Gun' back in 1988, so the use of F5s as 'MiG-28s' is explainable (esp since there was no MiG-28, so it's not like they're misrepresenting a real plane).
Gross innacuracy gets to me. Especially with regard to aircraft weapons...
Example: Hollywood seems to be in love with the AIM-9 Sidewinder (other AAMS are used too, but the 9 is the most popular). To them, it is the universal missile, which can lock onto anything from an individual person, to a truck, a building, a 50 gallon drum, and occasionally it's designed target (aircraft)... The 'hollywood' warhead produces an explosion bigger than a 2000lb bomb, and the launchers can auto-reload as needed...
For reference, in Tears of the Sun the F-18s took off loaded with Sidewinders (AIM-9) and AMRAAMS (AIM-120), then proceeded to lock and fire them on a formation of ground troops, producing explosions worthy of a B-52 raid and wiping out the enemy formation...
And to referr to Top Gun again, every missile fired in that final dogfight was a Sidewinder... Never mind that if the Navy was really serious about 'keeping hostile aircraft beyond 100mi' they would have used Phoenixes or Sparrows, not gone looking for a knife fight... But then there would have been no final dogfight, and Maverick wouldn't have been able to 'heroically overcome his fear of loosing another RIO'... So we see special 'hollywood tactics' used to make the movie ending better...
Another pet peeve is the over-doing of explosions.... Everything blows up like it was full of ammo and gas (just like every car that rolls over in a film explodes like it was hit with a LAW rocket)... Windtalkers and Tears of the Sun were classic offenders...
And then there's 'Stormtrooper Syndrome', where everyone (but especially the bad guys) can't hit jack shit... They blaze away on full-auto, but everyone allways misses... Even single aimed shots conveniently miss untill 'just the right time' in the movie plot where someone needs to be removed...
Finally, 'Hollywood Hi-caps' can get annoying too, ala Rambo and his magic regenerating ammo belt fot the M-60...