Ultra Magnus is my favourite Animated toy so I would definitely recommend it without hesitation.

I don't like Voyager Starscream (or Skywarp) that much but he's an important character. Voyager Shockwave (either grey or purple) is a more interesting toy.

I think Legends Bumblebee is a really nifty legends figure, but if scale's a concern the activator one is better, and it's one of the best activators too. The best Wasp toy was never released but made by one of our members using the activator Bumblebee.

If you do go for the Dinobots try and get the Japanese ones. I picked up all three while in Hong Kong because they are the only ones in my opinion where the shiny paint looks both subtle and right. But the toys themselves aren't that great all up.

As The Damned and i_amtrunks said, Cybertronian Optimus Prime and Oil Slick are pretty good figures.

Some top toys of the year threads from when the toys were originally out (2008, 2009) might help with decision making too.