Hard to get exact data, but fantasy novels have much longer average page counts than most other genres, though the amount varies within different fantasy subgenres. Epic is the longest, with debut word counts of over 150k words being pretty common (from my own recent digging around and ferreting out the page counts of recent debut). However, this doesn't mean that agents and editors are thrilled to get submissions for 150k or more word epic fantasies from unknowns. Epic is a notoriously hard subgenre to break into, and if you're subbing something long, it had better be darned good. I was pitching my fantasy novel at a writing conference recently (it's 120k words), and when I mentioned the page count, the agent looked worried and asked me to repeat it. When I did, she looked relieved and said, "Thank God, I thought you said 200,000 words the first time." She seemed to think 120k words was fine, though.
One problem is that the number of trade publishers that take fantasy novels with page counts much in excess of 120k are pretty small (mostly subsidiaries of the big 5), so if an agent gets even a really good epic novel that doesn't fit with what Tor, Orbit, DAW etc. are looking for at the moment, he or she is limited in terms of where else it can be sent.
The reason for this is that longer novels have a lower profit margin (due to the costs of editing, printing and shipping longer books as calibrated against what people will pay for a novel). Big presses can possibly get higher sales volumes to recoup these losses, but a smaller or mid-sized press is unlikely to sell more than a few thousand books.
My hunch is that if you want to break into epic fantasy, having a really good and tightly written manuscript that feels complex and epic, but that doesn't go too far over 120k words, could be quite helpful.
Though some fans of epic fantasy don't like shorter books and won't even look at them. It is a bit of a catch 22.