Please suggest me best company/site for buying voip number for switzerland.

Few sites i have visited to know prices and other tariffs
ie set up fee one time - 20 USD
monthly fee - 10 USD

if i divert my incoming calls to my mobile or landline (ie other than my PC) then usual voip charges apply.

Anything similar to the above or a better company/site than this

Get a VoIP phone. Connect it to your router or modem. Pay Switzernet 9 francs a month - you get a Swiss incoming number but can call quite a few countries for nothing (any many others for close to nothing).

Forwarding will cost you if you forward to your mobile. Why forward to fixnet? Dump it.

Siemens, for example, do some very friendly VoIP Gigaset models.

I've not had a landline for 5 years now.

I'm interested in your question as well but I'd love to see also what payment plan they offer. For example, I do all my VoIP with providers that do offer "pay as you go" plans on traffic and a small montly fee for DID.

Anyone can give us a clue?