Being in Paris as a backpacker is certainly a different experience to going with my parents a few years ago! I was completely shocked by drink prices, it was not possible to eat on the Champ Élysées, I was pickier about which sights I was willing to pay for and free walking tours are available (as you know right up my alley).
Wandering the streets of Paris with a London made friend was a great way to spend a couple of days. Staying at the same place as a friend made whilst in Scotland provides good laughs. Making new friends provides entertainment and a great experience in Paris. Finding cheap drinks and a drinking buddy in the hostel bar is sure to liven things up!
A creepy tour of the Catacombs of Paris was a completely bizarre experience. I honestly had no idea what to think. Seeing the bones of six million people arranged for the purpose of tourism (from the 1800's to now) is incomprehensible. But hey, at least it's not just our generation that has gone to crazy extremes on the tourism front! The catacombs is definitely one of the places you can't decide what appropriate photos would be (the bane of my existence!).
A highlight of my time in Paris was definitely a night time bike tour with a cruise. The aim of the game for 20 people on bikes and in fluro vests... To dominate the road! And yes I did buy the t-shirt. Thankfully no accidents to be had despite the fact I had no light. Only one angry taxi driver voiced his opinions quite rudely in French!