I sent an online friend of mine a link to some Halloween photos of my kids. She commented that they looked very sweet together. I was happy that soemone who didn't know them in person could see that, even if just through a few posed Halloween pictures.
Sure, they have scuffles. There are tears, usually due to someone hitting a flailing body part while they wrestle or run around the house. Until someone gets hurt (and someone always does), the wrestling is accompanied by laughter. They just have a great time together.
Personally I prefer their quiet play, but then again I never enjoyed being physical with my sister as a kid either. But in their quiet play I get to enjoy their great imaginations working in tandem. The'll devise elaborate scenarios with the animals or dolls or Playmobil figures. Eavesdropping on this type of play gives me such a wonderful feeling inside.
Another time that their love for one another shines through is in the morning. My son will often give his sister tender hugs when she first wakes up, and call her sweet little names. He has a great look on his face when he talks to her like this.
My daughter is very sensitive to others' emotions, and will try to comfort her big brother when he's upset. She is also quick to ask me to get him something if I'm buying her a little treat at the store, and she often initiates sharing a snack or something good to eat with her brother. Sometimes I catch her looking at him with such great love and admiration.
I have a great relationship with my sister. We faught a lot as kids; we came together as a unit when our parents were acting strangely (the prelude to their divorce). It's possible my kids will go through a fighting stage, but for right now I'm enjoying the sibling love.