My trip to Berlin was incredible. The city has a great vibe - lots of history, but lots of brand new things happening too, with the reunification of East and West Berlin occurring relatively recently.
I ended up sticking to recommendations mostly from Sandra Juto, a blogger recommended to me by Isabelle. She seems to have a good handle on the city, and recommends good walks, tips for transit and eating and drinking in a few neighbourhoods around town in her recently posted Berlin guide.
I also found the hard copy of Time Out Berlin to be incredibly useful, with solid maps and recommendations for eating and drinking in a pinch.
Here's my quick run down after nine great days in Berlin. (I apologize in advance for the lack of food photos...)
Restaurants and cafés:
3 Schwestern (Mariannenplatz 2, Kreuzberg) - This is one of those places on my original list that I actually made it to, during my first night in town actually. The food was pretty good (the portions are gigantic!) as was the beer, but what I really loved was the outdoor seating in the back. A garden with lights strung everywhere, and picnic tables scattered about, it was lovely. And yeah, it was in Mariannenplatz...
The Barn (Auguststrasse 58, Mitte) - There were a handful of places that seemed really American in style, and The Barn was one of them. Tiny and relaxed, they had great sandwiches and pastries to munch on, and they serve really great coffee.
Hudson's English Cakes (Boppstrasse 1, Kreuzberg) - I really loved Hudson's Cakes. The service was incredibly friendly, and I enjoyed a very tasty bowl of celery soup alongside an egg salad sandwich on the sidewalk patio. For some shots of the cute interior, skip over to Überlin.
CôCô Báhn mi (Rosenthaler Strasse 2, Mitte) - If you wander a little ways down Rosenthaler Strasse, you'll eventually bump into this small-ish sandwich shop. Their take on báhn mi is delicious, with super crusty mini baguettes and lots of sauce and spice being the star of the show.
Aunt Benny (Oderstrasse 7, Friedrichshain) - Of all the places I visited in Berlin, this place was my favourite. It was comfy and casual, with a menu of drinks and daily baked goods listed on the chalkboard wall behind the service counter. Mostly though, I loved their giant, cold brunch plates filled with cheeses, meats and veg, served with slices of crusty bread and a bagel (only available on weekends).
Monsieur Vuong (Alte Schönhauser Strasse 46, Mitte) - While the service was a let down here, I really enjoyed my food here, particularly the spring rolls.
Knofi (Bergmannstrasse 11, Kreuzberg) - I had a rather lazy morning before my afternoon flight to London, and ended up wandering around Bergmannstrasse (just down from my apartment) a bit. Knofi seems like a bit of an institution, with two shops/restaurants on either side of the street. While I wouldn't say the food is amazing, my plate of hummus, soft cheese, various salads and other treats was pleasant enough to nibble at whilst taking in the last of Berlin from their sidewalk patio.
Goulasch (Chamissoplatz 1, Kreuzberg) - I'm still sort of amazed by this place. It was one guy serving, cooking and washing up. Incredible. The menu consisted of two or three dishes, with a solid list of wine and beer to accompany. My beef goulash was incredibly tender and was full of delicious paprika, and the potato dumplings were perfect to soak up the sauce. A lovely last meal in town, just steps away from my apartment.
Other things to eat/drink:
Kadó (Graefestrasse 20, Kreuzberg) - Oh Kadó. I'm going to dream about this place forever. Bins, tins and bars of liquorice from around the world fill up this tiny shop. I can't wait to return.
Brezel Bar (Friesenstrasse 2, Kreuzberg) - I figured I couldn't return home from Germany having not grabbed a pretzel. Brezel Bar was just around the corner from my accommodations, and the pretzel I had was definitely enjoyable - a good crust on the outside, with a soft, chewy interior.
Other things to do:
Potsdam - It's easy enough to get to Postdam via the S-Bahn, and the best way to see the sites around the city is by bike (I'll still say this even though I took a tumble and walked around for the rest of the trip with some nice road rash on my leg). The Sanssouci Palace and gardens are beautiful, and be sure to wander down to the Orangery for a little more peace and quiet.
Insider Tours - One of my co-workers got me in touch with a friend, Brian, who works for this tour company during the summer. I can't recommend them enough. We covered lots of ground during our seven hour venture, and I would have missed half of Berlin had I not spent the 10 Euro on their "Famous Insider Walk". They meet in front of the Zoo each day at 10am.
As Sandra Juto mentions, Berlin is huge. Leave all footwear beyond your solid walking shoes behind.
Transit - I guess this isn't exactly something to do, but I thought it was worth mentioning anyhow. If you're in town for the week, I'd seriously recommend picking up an ABC card (there are automated machines at each station). For 34 Euro you can travel around the city all week (the C part allows you to travel to the airport and to Potsdam) on the U-Bahn, S-Bahn and bus. Seriously worthwhile.
The market at Boxhanger Platz - I found this market to be a bit of a mixed bag. There's lots going on, from crafts, to local food (to random imports), to coffee and food carts. Nonetheless it's in a much less touristy part of town, and I found it perfectly pleasant to stop at Aunt Benny for brunch on the way, wander around then head down to Alexanderplatz by foot.
Boat tours - I booked my boat tour via Berlin City Tours, which offers tickets from all the different companies offering boat tours along the Spree. My tour took place in the evening, which I loved, however boats travel throughout the day. One thing I would recommend (especially if you've already done some sort of walking tour) is to find a tour without the running commentary.
Freiluftkino or outdoor movies - A group called Freiluftkino Berlin runs three different 'theatres' throughout the summer. While I was in town, they showed Moonrise Kingdom at the Kreuzberg location (behind the building that houses 3 Schwestern). Tickets are ~ 6 Euro, which gets you in, and also gets you an incredibly comfortable deck chair (and a blanket if you're quick). A trailer kept everyone supplied with popcorn, beer and wine.
Accommodations, travelling alone and service:
As with Portland/Seattle last year, I went with a vacation rental that I found via Airbnb. Friends have reported mixed experiences, but I loved my apartment and hosts, and wouldn't hesitate to utilize the site again.
Now that I've ventured out on my own, I have to say travelling and eating alone are vastly underrated. Berliners are incredibly friendly and helpful, and I had no problems walking around Kreuzberg or Mitte anytime of the day. Service around the city wasn't incredible, but I felt well taken care of at any of the restaurants I visited, and no one batted an eye at me eating alone (unlike London).
Incredibly helpful blogs:
Foodie in Berlin (good for both London and Berlin)