By recommended I mean what is the standard for it to be not too long and not too short. I know I should write until I am finished but I want to take practicality into account as well. Mainly when the book spans in a series.
I agree with Shan--while the word limit for fantasy is usually more elastic, you are a debut author, and a huge word count is not going to make for an easy sale.
That said, a lot of the fantasy submissions I see are not long enough. Paranormal and fantasy novels, nine times out of ten, require more world building and exploration than a shorter novel can carry, and readers love a rich new world. The best ones I have seen (and read, as published) are around the 100k mark--sometimes a bit more, sometimes a little less. The trick with structuring a fantasy novel is to weave in the exposition with a very light hand, so it always feels as if the action is moving things along. Joe Abercrombie, while not my thing, is very good at this. In other words--the book might look like a doorstop but it's never a slog of a read. It's an indulgence.
Here is pretty much THE post on word counts from publishing ace the Swivet: http://theswivet.blogspot.com/2008/03/on-word-counts-and-novel-length.html She thinks you can get away with 120k for epic fantasy. Personally, I'd err on the lower side of that, purely because as an untried fantasy author, you're probably prone to waffle (been there, done that, never letting aaaaanybody see that novel, lol). If your betas come back to you and say "more here, please!" then you've got wriggle room.
In summary: the trend for novellas is not fantasy's friend, not unless you're building on an already-established world. Structure your exposition well, keep your plot moving, and aim to cycle through three acts to a sweet spot around 100-120k. If you're good...your editor will take it from there :)
For novels in general, the accepted word count is 70-80,000 words.
For fantasy novels, you are allowed to go slightly above this limit, but unless you are an established author, I don't recommend going too far above. I would limit the book at 100,000 words to be safe.
That said, I usually find it hard to even reach the lower limit, and looking at the large amount of fluff in many books, I'm guessing so do other authors :)
In the comments to one of the other answers here(can't remember which one), many people noted they would happily pay for a novella, just to avoid all the unnecessary padding and fluff. Keep this in mind when writing - one of the risks with a huge book is, unless it is truly great, most people will just ignore it.
I got a response from an agent today, saying that my book, The Wind-Weaver's Quest, had too long of a word count. It is 131,000 words long, and I was thinking it was too short, especially since it tells the stories of four different characters. I really didn't think of having the amount of words being something that would keep it from selling, especially if the writing is good.
But you can see from the agent's reply that the appropriate length is important if you want to sell your book, especially as a new author.
75,000 word to 100,000 for most novels. Fantasy is about 85,000 to 125,000 words. I would say aim towards the 125,000 for your first daft. Then on your second edit try to cut 5,000 word from each part if you have 3 parts to your story. So example first edit I have over 40,000 words or 160 pages. Then I would try to cut 20 pages from that. So by the second edit you would have 420 pages or 105,000 words.