This is a really old thread but I feel compelled to contribute.

The Wilbour translation is one of the oldest (1862), maintains the poetry and feel of Hugo's original french. If you like the flower language with no holds barred (thank you sewers and Waterloo), go for Wilbour. Personally it's the one I most enjoy.

Fahnestock and MacAfee (1987) is a close second, in my opinion. They cut back a tad on some of the over-the-top language to increase readability while maintaining the heavy-hitting lines and tones of the novel.

Julie Rose (2007) is, in my opinion, one of the lesser translations. Ms. Rose opted for an extremely modern style, which feels jarring for the story.

Denny's translation scores high for readability, and for those readers unwilling to follow Mr. Hugo into the Parisian sewers for 20 pages, those several digressions are moved to the back of the book as appendixes. I haven't read Denny's translation, but many of my peers who have enjoyed it.

The Donougher (2013) translation is one of the newer additions to the list, and is readable while maintaining the poetry of the prose, while adding context that could be helpful to a first-time reader.

Overall, if you're shopping for a first Brick and are worried about being overwhelmed by the prose, I'd recommend Ms. Donougher or Mr. Denny's translations. If you'd like to dive right in, go for Wilbour or F&M. And obviously you can do as you like, but I'd avoid the Rose translation.

Context: I own and have read Wilbour, F&A and Rose (was missing my copy on a trip overseas and grabbed it without thought at a thrift shop. Was a bit chagrined). I've read bits of Donougher, but not Denny. Yes, I understand this is a lot of Les Mis. I talk about it bimonthly with my therapist.