if by "companion" you mean...
...medium format, go for a hassie/ rollei TLR
...digital, go for the M8
... hold another FL, go for the 0.58/ 0.72/ .85/ M3 whatever suits you best
... a camera that you won't be afraid to smash yet takes wonderful pictures, go for the konica Hexar AF
... a camera to take picture of bugs getting horny on flowers, get an SLR+macro lens
... a camera for urban landscape, go for LF
... something to shoot in very low light, buy a tripod (yeah, I know, dumb advice for an MP)
...something to listen to JS Bach while you're shooting, get an Ipod
... something to limit your uncontrolable bursts of buying frenzies, get married
etc
etc
etc