My first Pentax was an ME Super. A great camera, full of features. Sadly I couldn't afford the pentax lenses and opted for a Sigma 24mm wide angle, followed by a Vivitar Series 1 700/210 Zoom
The ME served me well on many a trip around the globe (and I still have it)
Photography took a back seat for a while whilst the family were growing up. However I got back into things a few years back with a Pentax iSTD - well 3 of them, closely followed by the iSTDS. Now, having picked up a K10D and a K20D to follow on, I am firmly back in the Pentax mould. My collection of FA* Lenses could never be replaced - I have got them all - except for the 250-600 zoom that is.
Along with all the Pentax accessories, Flashes and Converters - leaving pentax isn't an option. To be honest - I have no idea what I would change to if ever the situation arose. As long as Pentax keep the backwards compatability with their camera/lens combinations I see no reason to change. (That K7 has my name on it!!)