Some of my picks would be.

Stargate
Total Recall
Top Gun
And some others I can't think of right now.

Stargate was never really a big hit...had a good opening weekend, that was about it.

Although the reasons have been well documented by those involved, I'm a little shocked sequels to E.T. and Forrest Gump never happened.

There was talk of a Total Recall sequel, based on "Minority Report" no joke. I believe it is mentioned in the commentary that the setup would be Arnold would be in Mars, and the psychic mutants would be the pre-cogs.

At that point in Arnold's career, you gotta remember the guy was demanding and receiving astronomical sums for his salary. That pretty much killed a lot of films he was associated with.

For his next action film, T2, the guy received $15 million in salary and I believe that Carolco bought him a private jet as well.

Titanic

Top Gun!!

Super Mario Bros.

Come on, this movie is dying for a sequel.

Innerspace
Return of the Jedi
Legend

and

Big Trouble in Little China

Well, Stargate doesn't have a movie sequel. But I don't imagine it will, cause there is that long running television show Stargate SG-1 which is, by all means, a continuiation of that franchise. So I'd say that's practically a sequel (just much more of it).

I would add Ghostbusters to this list...I do know very well why this movie fell through but, I don't know...I always figured it's Ghostbusters...they've gotta make another one. I like Bill a lot, but he could've thrown us all fans a bone.

Definitely, TOP GUN!

The Fifth Element

It didn't even make back its budget in the US.

Actually, it's U.S. cost was little more than $12 million in terms of investment as it was financed mostly with foreign dollars. Also, you only posted the money it made in the U.S. Overseas it more than made its budget back.
I recall reading an article in which Fifth Element was mentioned as being quite profitable for Columbia.

My picks for sequels:

Top Gun-don't know why they didn't make another one of these

Basic Instinct-wasn't there a sequel to this planned that fell through and became another movie altogether?

BeetleJuice-this pretty much put Burton and the whole offbeat comedy concept on the map. Don't know why they didn't make another.

Twister! made huge bank...cant believe they never made a sequel...guess Jan learned his lesson with Speed 2...

ID4!!!!!!!1!!11!!!!!!

Agree on SG-1, much better than any single movie/sequel could have turned out to be. However, there is talk of taking the actors from the series to the big screen

WRT the main question one that comes to mind is Starship Troopers but it seems they are doing that (see the main forum for the thread). The original Italian Job could have used one too considering how it ended

I thought Tim Burton's POTA was going to have a sequel despite its crash after opening weekend without Burton attached. Maybe the general public's venemous response made them think otherwise.

I guess I missed something here (or maybe the sarcasm):

http://www.imdb.com/title/tt0097428/

I'm still waiting for Terminator 3.

I was meaning why they never did a part 3. It was in development forever, almost seemed like they were going to make it. I know why it didn't get made, but I just figured someone would figure something out cause there's money in it.

Bill Murray got too important to make a third Ghostbusters.

Pulp Fiction- I'm glad though

Twister 2: The Revenge?

Stargate Total Gross: $71,567,262 USA

$125,000,000 (Non-USA)

$196,600,000 (Worldwide)

That is a big hit in anyones book...

So yes I am surprised that there was not a second one. But I agree with what was mentioned about the TV series...

The Sixth Sense

-THE BREAKFAST CLUB

20th anniversary is next year... A reunion film would be fantastic!

-Another Jack Ryan film with Alec Baldwin.

-There was talk by John Cusack over a sequel to GROSSE POINTE BLANK about a year after it came out. I think it was said that Cusack and Co. were actually pounding out a script too! Nothing ever came of it.

Give it some time.