I think there's a near-infinite combination of speakers, rooms, tastes, budgets, what-have-yous, such that any given individual could spend way too much time worrying about whether there's a better way of doing things, rather than simply getting on with the enjoying. From the previous posts I find it great that so many different approaches result in the same thing: happy listeners.
But to answer the question I have probably tried most combinations (and have the previous experiments sitting in storage right now to prove it) and for some time now have preferred identical large full-range speakers, identically-placed (ie. all vertical) in all positions, including the centre - because I can!
For multi-channel movies and music I run the full monty. However for more intimate stereo listening I've very recently set up a separate 2.1 system within the confines and construct of the same main HT that houses the 7.1 system. Again because I can.
Jeff Mackwood
7.1 system speakers: 5 stacks of Koss CM/1030 (2 per stack - 10 speakers in total) for front L/R/C and side surrounds; 1 pair of Paradigm Titans as rear surrounds; 2 Velodyne Servo 1200 subs, 1 B&W ASW-1000 sub; and an SVS PB13 Ultra sub thrown in to boot. (There's also a Yamaha YST-SW160 sub, but that takes more explaining than the others.)
2.1 system speakers: 1 pair of Koss CM/1010; 1 SVS 20-39PC+