I absolutely hated the fourth book from the very mention of "little nudger" and I will forever hate that I got drawn into Steph's world then have it end the way that it did...
On the other hand, I loved how JK ended the series, I like her writing, but it took me a really long time to get into... maybe because I just hated how young the characters were in the beginning... it just took them a long time to progress, but the last two books of the HP series were great, tons better than the ones before.
I know of another series that may be hitting the big screen... "The Mortal Instruments" trilogy/now series since the announcement of the 4th book... by Cassandra Clare (who got her start writing HP Fan fiction, btw).. doesn't have the depth of romance that Twilight had.. nor the descriptions and whole complete other world that JK had and at the slower speed.. so, if done right I believe her series will be better than Twilight... I think the script writer for Twilight needed to be replaced immediately after Twilight ended and New Moon started...
But anyway, from a book and movie stand point, I liked HP better.. but the romance of Bella/Edward and Bella/Jacob drove the books.. and romance and internal conflict is more appealing to me..