What´s better for SEO: one website for each product or one large website ?

[intex]

Hi there,
out of historical reasons such as limited traffic, limited space, expensive extra domains etc. we came to the situation, that we today have a company website plus x websites for each product. The company website has a pagerank of 3, the other have a PR 2. All sites are inter-linked.

So we ask ourselves if today it wouldn´t be better to centralize all our stuff on one big large site, since today there are no traffic limitations at all and the space limits are out of reach.

If one site/space would be better, what would then be preferrable ?
a) one site with x domains for each product
b) one site with only one or two domains and a bunch of subdomains for the products

Thanks in advance

[JessicaJohn]

One website with comprehensive knowledge of every product related to your business because your user or customer can easily navigate on your website and get information other products.