I'm not sure how affordable it is but Fort Edmonton Park is a really cool place. They have the old fashioned street car running in the summer and in the winter they offer carriage rides. We were looking for an indoor/outdoor reception site as well and had some issues. I really wanted an old barn to rent but I couldn't find one. My fiance is in the military so we decided to do our reception at Warrant and Sergeants mess hall. Our ceremony is at the St. Albert Botanic Park and we paid $225.00 which is a great price.
There is the Sandhills Community Centre as well. It is a little out of the way, which is why is such a great deal. It has a great indoor/outdoor space and is very well priced. Friday, Saturday, and Sunday only cost us $350 I think. It's not "beautiful", but you can make it beautiful inside. It's just plain, not run down or anything. It also comes with the option of caterers already with the hall, and their food was amazing! The Whitemud Creek Hall is beautiful, our only problem with that site was that is was quite small and very expensive ($1000 for Saturday night). It might be better priced now though.
Check out Chateau Louis. They have a beautiful outdoor gazebo for ceremonies, as well as a spacious outdoor area for receptions. They also have a gorgeous banquet room if you are looking to have your reception inside.
The Lodge at Snow Valley is beautiful in the summer time! They can accommodate both ceremony and reception at the same facility, the reception space is really pretty with big windows letting in natural light and looking out onto green space in the valley. They are a little pricey, but the food is amazing and they take care of everything. Definitely worth looking into.
Can't beat the whytemud creek community centre interior but the Riverdale Community League is a pretty building, super central location - and is right on the river with a nice outdoor area. :) It's also 1/2 the price ($350 as opposed to $700-$1000)