Mac or PC - Its really down to which one you like most. Seriously, I prefer Windows & just can't get on with the Macs we have at college, but I know people at college who are just the opposite. Terragen - free obviously :) - poor animation, no trees etc. Vue - Camera hard to 'get right' during animation but Vue Pro fixes that if you have Lightwave/Maya etc. Great trees. Fast renderer. Import models. Bug fixes galore in the future for Pro. Bryce - Sorry, don't know, but if its no longer developed then its future is limited.