ROTJ is fine, I often prefer it to ESB. Then again my usual answer to "What's your favorite Star Wars?" is "The one where they fight. In space. With lightsabers." ROTS is quite superior to AOTC, which breaks the "curse", if you look at Star Wars as two trilogies.
Love Last Crusade a bit more than Temple of Doom. Actually I'd even put Crystal Skull (as off the rails as it gets) somewhere slightly above Temple of Doom. Don't get me wrong though, I quite like TOD :P
Mad Max Beyond Thunderdome gets a lot of flak these days (mostly for featuring "too many kids" and "not enough smashy smashy"), but yeesh, its a good movie. As I recall Siskel and Ebert preferred it to both of the previous films, with Siskel quoted as saying its "a series of films that just keeps getting better and better" and Ebert calling it one of the best films of 1985. Tom Hardy's the new Max Rockatansky for those that didn't get the memo. :P
I'd easily take Back to the Future Part III over Part II. Same with TMNT, because yikes Secret of the Ooze is...I mean its fun..aside from that "Ninja Rap" bizness... As I recall TMNT III was better, but its been years and years. (Edit- for those wondering, yes, the CGI TMNT -is- supposed to be a part of the same continuity as the original live action pictures, just years later. That's one reason you can get all 4 in a set now.)
Highlander III at least makes -a little- sense in relation to the original, where (any version of) Highlander II is just a complete mess. For anyone interested, Highlander 5 was actually somehow worse, IMO anyway.
Sure Leone's Dollars Trilogy isn't a trilogy in a certain sense, but in that case neither is Mad Max or even Nolan's Batman series. If you're watching the Dollar's trilogy as a -trilogy- though, keep in mind you start with The Good, The Bad, and The Ugly and finish with For a Few Dollars More, which is fine by me since I prefer it, gasp). Either way you do it, its untouched by any "curse".
I'd sooner watch the dumbed-down kiddified RoboCop 3 than the crazed-nightmare that is RoboCop 2, though I consider neither to be a true sequel/canonical. Same goes for Highlander, though I can still at least enjoy its sequels in an Elseworlds sort of sense. :P