Well band Of Brothers is a mini-series for TV so it's kinda like a 10-hour movie split in 10 parts.
But yeah I know what you mean, I feel compelled to get every movie in the series, even if I'm not a fan of some of the sequels. Although
Terminator 2 kicks the previous and following ones' asses.
Thankfully, I usually buy boxsets so that I feel like it was an easier buy to make, as I didn't have to go through the process of acquiring sequels I'm not too fond of.
And by the way, you need to give the two Pirates Of The Caribbean sequels a chance, you might love them.