There are two sites that I would recommend: www.hollystar.com (based in Neuchatel) and www.moviemaxx.ch (based in Valais). These are (in some cases) the same sites you will navigate to if you try some of the web addresses in the other posts.
Depending on the membership you take, rentals costs range from approximately CHF 4 (Moviemaxx has a large selection at CHF 2.90 per movie) to CHF 8 per movie. Both operate by post -- i.e., you create an online account, you select your movies (DVD or Blu Ray), you receive them by mail (in theory, the following day -- although this depends on the postal system and where you live) and you return them (for free) by mail. With Hollystar, your account is linked to your credit card (VISA and MC only) and charges are made to it when you order. With Moviemaxx, you pay by Bulletin de Versement (BdV) which arrives with the movies.
Hollystar has the best selection of movies -- by far. Their catalogue of foreign and older movies is broad and deep. However, you can only order two films at a time. And ordering a Blu Ray movie adds a CHF 1.50 premium to your bill per film. Moviemaxx has the advantage of letting you order up to 8 movies at a time, and you need only pay within 30 days.
Both companies will not let you rent additional movies until they receive back those that you ordered.
Hollystar has a slightly more robust website. And it's prettier. The Moviemaxx website can, on occasion, get stuck, forcing you to start again. Both allow you to create a wish list of movies from which then to rent. Hollystar will also let you reserve a film in advance (for CHF 1 extra) or receive alerts when a film you want to rent is available. A similar secured "turbo" reservation at Moviemaxx costs CHF 2 per film -- and you are guaranteed to get the movie within 10 days. On the Moviemaxx website, you can sort your wish list by title, availability and release date. Strangely, you can't sort by title on Hollystar but, helpfully, you can sort by age limits and language (both dialogue and subtitles). When you rent a movie from your wish list, it automatically disappears from that list, but you have to mask already-rented movies from your wish list at Hollystar. Hollystar offers a comprehensive VOD service (streaming video to your TV, moviebox or PC/MAC) which Moviemaxx does not. Moviemaxx offers language support in English, French and German; Hollystar only offers French & German (this can make searching for a movie, with a different title depending on the language, problematic, requiring you to sometimes have to search also by actor/director).
Customer support for both is prompt and helpful, even if you only communicate in English.
Bottom Line:
Both sites do well on price per film. Hollystar wins hands-down in terms of breadth of movie catalogue, especially foreign (beyond English) and website reliability. Moviemaxx wins in terms of English language website support, the number of movies you can rent at a time, some search features within the website, and payment terms.
But why quibble -- use both services and get the best of each!
I do not think Hollystar is that great. I signed up for free 1 month trail and have been trying to contact them by email/phone since a week to cancel but with no luck. No one picks the call center number. Its always busy.
I would not recommend Hollystar based on my experience.
Cheers