-Wii with Wii sports
Wii Sports has a lot of sports, but in fact all you'll like is tennis. Or maybe boxing. Bowling, baseball, and golf are just not fun. But tennis is awesome to enjoy with your friends and family.
-Wii play including extra remote
Never played Wii Play, but I heard it's good.
-extra nunchuk
You'll definitely need it.
-Red steel
You might have to worry about the control cuz it's pretty hard to aim and move with Wiimote at first. But once you get used to it, it'll be ok. But I don't recommend it personally.. But there are a lot of people who loves that game out there, so it depends

If you're buying that cuz you just want to shoot, you'll get pretty stressed out at first cuz of the control like I said. I don't know how old your sister is, but I'd recommend you to just get Resident Evil.
Or.. Wait till Metroid or Umbrella Chronicles.
-Mario strikers
Fun game! It's not serious like FIFA or something like that. It's really casual and still fun.
1) Also does it come with a memory card?
I think it doesn't... But I never needed one unless you're going to transfer your game save data to another Wii console or transfer video, music and stuff.
2) Are there alot of annoying wires hanging everywhere?
Well.. Not really. But it really depends. The sensor has a wire. And also you need another wire(you could call it three cuz it splits to three but well..) to connect your console with TV. Finally the power cable. And..That's all as far as I know... If you want to buy Nyko Wiimote charger, then there's going to be one more wire.
3)How do I transfer videos, pics and music on the console?
You can simply put your media files in SD card.(that's the memory card used in Wii) But I'm pretty sure that you won't be able to watch video unless you transferred the video directly from certain digital camera. And about the pics, there is Photo Channel in all Wii console, so you can view your pictures in SD card and also edit it.