"Best" Quixote translation?

My mother is reading Don Quixote in English with one of her reading groups, and asked me what I knew about different translations. I had to reply that I knew nothing, as I had read it in Spanish, and had never had the occasion to think about "the best translation" before. I started poking around (hey, the Wikipedia entry is good!)and after looking at some scholarly and not-so-scholarly discussions of the history and quality of the very many English translations, I decided that the one her group is reading (the Edith Grossman translation with Alan Bloom's introduction) is probably, in fact, the best for their purposes; it is not a scholarly edition with footnotes explaining every proverb and reference and arguing with past translators' versions, but it is a accurate, and most importantly, a lively and FAITHFUL translation that captures the tone and spirit of the work. Here is what Edith Grossman herself says about translating literary texts (she has translated many Latin America authors, including Gabriel García Márquez):

Fidelity is surely our highest aim, but a translation is not made with tracing paper. It is an act of critical interpretation. Let me insist on the obvious: Languages trail immense, individual histories behind them, and no two languages, with all their accretions of tradition and culture, ever dovetail perfectly. They can be linked by translation, as a photograph can link movement and stasis, but it is disingenuous to assume that either translation or photography, or acting for that matter, are representational in any narrow sense of the term. Fidelity is our noble purpose, but it does not have much, if anything, to do with what is called literal meaning. A translation can be faithful to tone and intention, to meaning. It can rarely be faithful to words or syntax, for these are peculiar to specific languages and are not transferable.

Why a new translation, when several were made right after its publication? Well, because English has changed a lot in 400 years, and Cervantes is, above all, a modern writer, and reading the original is an experience of great pleasure.
Without having looked at any of the texts myself it seems to me as if Grossman has done two important things: rendered the text in English that is colloquial and accessible, and captured the tone and multiples voices of Cervantes' text. Many people also had great praise for the audiobook read by Guidall.
Wikimedia has a lot of images of Don Quixote including the wonderful series of illustratioins by Gustave Doré.

Here's an interview with Edith Grossman
on translating Cervantes.