With the news of Oracle buying Sun who is the fairest (best acquirer) of them all?

Three big IT companies come to mind, one I know relatively well :
Oracle : around 50 since 2005, and apparently the rule is 60 days to integrate.  Impressive.
Red Hat (*) : 15 in total currently, though I think that is short at least two: Ars Digita and Sistina
Cisco : lots, 16 of them beginning just with the letter "A"

Am interested what metrics there are to measure the relative success of A&Ms.  Heard it said more than once that Cisco is particularly good at buying other companies.

(*) Unlike Cisco and Oracle, Red Hat does not list its acquisitions on its site, so used wikipedia instead which looks about right