Back to the original question...
If you ever plan to do a pub crawl from Alte Oper to Bornheim then I would recommend:
Bodega Barcelona (tiny bar near Jazz Keller) for some nice sangrai (kleine Bockenheimer str.). Good place to take a date.
Around Hauptwache:
Studio Bar for the Versace crowd.
Cafe Karin, Lux and a couple of others but forgotten their names for now
Luna Bar for a nice cocktail (between Hauptwache and Konstablerwoche)
Mosaic for smoking some Turkish waterpipes (south of Konstablerwoche)
Jazil also for cocktails (Konstablerwoche through the small passageway next to Deutsche Bank)
Sandbar (at the bottom of Sandweg)
MiniBar and it is tiny (at the south end of Berger Str.)
Flippers for late food & drinks (Berger Str. between Merianplatz and Hohenstr.)
Destino for pretty people (past Subway Sandwich on Hohenstr.)
Yours Sport Bar to watch some football (back on Berger Str., north of Hohenstr.)
Schönenberger with the large mirrors and wooden tables (past Bornheim Mitte)
Actually all the bars on Berger Str. are quite good, not that I am biased because I live just off this street.
But most of these have been around for awhile, so maybe you tried them already.