Another addition to this list (or to a superlist comprising several related lists):
as in, "OMG, I looooooovvvvvvvvvveeeeeeeee that show!!!!! :P"
I see this indignity being visited upon any number of words: love is just the first example that came to mind. The problem is that while multiplying letters in a word is a perfectly valid stylistic device (depending on the formality of the context, of course), some discrimination has to go into which letters are going to overflow all over the page. The O and the V are OK in this context, but the E? What we've got written down here is not a long one-syllable word, but a long two-syllable word. Extending the silent E makes it not silent anymore. The word above would rhyme with movie.*
That is unless someone really did shout, "Surprise-eeeeeee," which would be legitimately surprising [slash, terrifying].
* Actually, love in fact is either a great or a terrible example because the sound we want to extend is represented by the O, but writing multiple O's results (as any I-Can-Reader could tell you) in an oo sound, as in moo—such that even loooooooooove would be wrong: you'd have to pronounce it not like a long love but like a long loove (U with a line over it).