The Hyatt and RC are both very good. I've read good reports on the Forte but not been in yet - however, RF properties tend to be premium priced even over R-C's etc (albeit in Berlin it is still likely to be cheap!). The Hyatt and R-C are next door in Pots Platz whilst the RF is five mins walk away by the Brandenberg Gate. More shops / restaurants etc in Pots Platz if that is important.