cagli my dc are almost same ages as yours (just turned 7 and 10), and they've been playing Dominion for about a year now (and absolutely whupping us).
I love Priests of Ra, we have that too- did you get to see Reiner Knizia at games expo?- I really like the auction mechanism in it.
cheesewhizz card games we like are chinese poker (which is sort of mah jong with cards, using poker hands- need 4 to play though), my children adore cheat, but they're too good at it for me to play them any more.
We also have Star Realms which is a good two player game. You can play multiplayer if you buy two sets. We have hanabi, an indie game called 'village in a box' which I adore, though we had to mod the rules slightly.
We have TTR original (which I think is still the absolute best), and the UK/Pennsylvania expansion. I find UK v hard, as there's so much to remember (the technology stuff, keep forgetting to get cards), but the Pennsylvania TTR is just awesome, I love the stocks part, the children love it too, so we probably play that and original equally most.
I am really not a fan of co-operative games, though my children are- they love pandemic. We also have The Musketeers du Roi which is a co-operative, and quite good (one player is Milady, all the rest are Vs her, and take the roles of the musketeers, treville, and D'artagnan).