For family/friends house parties I will use my EF 50/1.4 (I have a 7D). 50mm is a little to long for me in the average house, but it's great outdoors for leaving some space between me and my subjects. I've found 24mm (giving a 38.4 35mm FOV equivalent) to be a great focal length for use in rooms. For this particular purpose 24mm on full frame would be too wide for me (like 15mm on crop). I would usually like to include some of the environment surrounding my subject. The wideness and deeper DOF of the shorter focal length can help with this. Since I don't have anything wider than 50 for my SLR right right now, my G12 comes in when wide is needed. The 24L II is currently #1 on my wish-list. I haven't heard enough good things about the 28/1.8, so I'll save the $500 and be about 1/3 on my way to getting the 24. There's a member who frequently posts pics of his son in the 24/1.4 II sample thread, and his 24II and 7D combination seem just right for that.