The 630 - only because there weren't many (if any) changes between the model years. The 635 and 630 are almost identicle. It's not like you're gaining HDMI with the 435 over the 630. The 435 puts out 80 watts per channel in stereo mode, while the 630 gives you 90. You also get 10 more watts a channel in sourround mode with the 630. It's not a ton, but for the same price, why not go with the 6 series? Both are beefy units at 39lbs and 41lbs respectively.