[LaPistola]

CS5 has more features and if it was me (ok i have CS5) but it would be CS5.

Elements is far easier to use and is more user friendly but if its true multiplication power you want then Elements lacks Puppet warp, Content aware technology, the vanishing point tool, HDR, channels palette, automatic lens correction, warp tool, better edge detection for tools and I bet there are more. CS5 also help speed things up with programmable actions and stay non-destructive but flexible with smart filters.

If by manipulate you mean correct angles, crop, correct exposure and remove the odd spot you will not need at the whistles that come with CS5 so go for elements.

Just to throw a 3rd option in there, Lightroom. I use lightroom more as it keeps my collections and photos organised, has publish services I define which makes exporting/converting faster and it uploads to online galleries, has what I think is a slightly better RAW editor than camera raw and everything is in one place. If I need the power of CS5, lightroom opens the file in CS5 for me and then stacks it with the original in lightroom so I can quickly access it again.

EDIT: With lightroom I can edit a lot photos quickly which is another reason why I use it more then just Camera Raw and bridge but its only: exposure correction, horizon fix, crop, colour shift, white balance correction etc. If you need more manipulation power then its Elements or CS5 from Adobe's offerings