Berlin club suggestions:
1) Tresor. Yes it does get its fair share of tourists (although Berghain is now officially the most tourist filled club in Berlin) but is definitely worth checking out as the Tresor name is part of techno history, although in my opinion the label has declined in recent years, the best thing they've put out lately was Christian Vogel's Neverengine album. Dates of note coming up would be Scotland's finest Dave Tarrida on the 15th of August. The place Tresor is at now isn't actually the original club, that was knocked down a few years ago.
http://www.tresorberlin.de/2) Club Maria. Another "non-hip" club, due to its lack of minimal techno I suppose, which in my mind makes it better than most. Maria is usually where they get the more alternative line-ups. This Saturday Cylob from Rephlex Records (the label Aphex Twin co-runs) will be playing as well as Skam Record's Rob Hall (Skam is where Boards of Canada started off before Warp poached them)
http://www.clubmaria.de/3) Berghain. Currently number one in Resident Advisor's "Top 100 Clubs", expect two hour queues unless you get there pretty early or pretty late. Full of tourists, but still pretty decent. The main Berghain floor is home to the harder techno (Birmingham's Surgeon is playing there in September, one night I'd definitely recommend), the Panorama Bar is more geared towards the housier end of things (best thing I saw there was the Environ label night a few months ago). I I find the music mostly a bit dull myself, I also don't think most people go there for the music but more for the atmosphere.
http://www.berghain.de/4) Watergate. Definitely "fancier" than the other clubs mentioned so far, Watergate gets some good line-ups but most of them are of the minimal techno (eg Troy Pierce played last night) or tech-house (Get Physical, Mandy etc) variety. They've got a pretty cool looking ceiling with crazy lights upstairs. Flicking through the line-up I'd say go check out Matt John on the 28th of August.
http://www.water-gate.de/5) Week-End. Some people go mad for this place, I personally think it's pretty good but not amazing. The roof is open in summer which affords a great view of the construction work going on in Alexanderplatz. Music policy is close to Watergate's, the Mobilee Lovers weekend on the 9th of August looks pretty good. They also have Moby (Moby!?!?) playing there on the 7th of August! I don't know whether to cry or laugh...
http://www.week-end-berlin.de6) Club Der Visionaere. An Irish girl I've been hanging out with told me that every single time she goes to this place she picks up a new guy. It's a great small bar/club type thing on the River Spree, very relaxed atmosphere and free in every time I've been there. More a small private party than a proper nightclub, well worth checking out and one of my favourites on this list. Mostly outside though so not so great when it's raining. Music was a mix of plinky plonky Perlon style house stuff, but one night the DJ played a Glass Domain track which totally knocked me off the seat and made me get up and do a robot dance.
http://www.clubdervisionaererecords.com/source/main.htm7) Icon. I've only been here once so far, the actual club has a pretty cool underground cavern feel to it, music policy seems to be drum n' bass or else Ninja Tune style instrumental hip-hop (I saw DJ Food play the time I was there, bit of a disappointment actually). I'd like to check this place out again sometime, could be a nice alternative to the minimal techno you hear at most places in Berlin.
http://www.iconberlin.de (site seems to be down right now)
8) Birthday Party Berlin. Mentalist breakcore/noise/anything goes club co-hosted by DJ Donna Summer (no, not that Donna Summer). DSP merchants such as Kid 606 were booked to play the last time, the venue changes so check their site for the next show.
http://www.birthdaypartyberlin.com/9) Bar 25. This is another great club by the river, I was actually here four years ago (during Love Parade Week in 2004, the actual parade was cancelled) and one of my friends was sitting on a windowsill and fell off it as he became unconscious due to partying too much, we stuck a donner kebab into him and he was fine though. I haven't actually been here since I moved to Berlin but it's on the list. Check their website for listings.
http://www.bar25.de/10) University of Bohannon. I think this is mostly a more commercial hip-hop (uh oh!) style of club, but once a month these guys come in and run what I can only describe as the best night in the universe called "Rap History Berlin". Each month they do a year (they're doing 1988 in August, it was 1987 the month before and so on) and they only play old school electro, hip-hop electrofunk music from that year! I'm a huge fan of this type of music so I was in my element the last few times I was there (if names like Mantronix, Man Parrish, Egyptian Lover, Ultramagentic MCs mean anything to you then you'll love this place). Egyptian Lover actually played there for the 1984 night in April which was the best night out I've had in Berlin so far. Berlin doesn't get much proper electro (proper electro being the kind that's made from 808s), hence why I love this place.
http://www.myspace.com/raphistoryberlin11) Arena Club. I haven't actually been here yet, but saw a few posters with some half decent listings for it so may be worth checking out.
http://www.arena-berlin.de/12) Dr. Pong. This isn't a club at all but I DJ here every so often so I thought I'd stick it in (hey, I'm writing this guide I'm allowed some advertising space!). It's a small bar in Prenzlauer Berg with a ping-pong table, I'm playing there this Sunday (3rd of August) and also in September on the 6th (a Saturday I think) and probably once a month-ish after that also.
http://www.drpong.net/So, that's all I can think of at the moment! Berlin is a veritable smorgasbord (that's what they say in American right?) of clubs and places that play music. Whatever your taste I'm sure you'll find something good. On the "Berliners in clubs are unfriendly", I'd say that compared to Americans, who are usually more quick to talk to you in a club, native Berliners can seem a little cold but any effort you make is usually well rewarded, just don't be put off by a few curt answers at the start of a conversation! Speaking German probably also helps, I am ashamed to say I don't speak a word of German yet but then again I'm Irish and we have special powers when it comes to talking to strangers in an alcohol fuelled environment.
I'll update this list if I find anything else good, enjoy your time clubbing in Berlin!