berrybuzz,colorID, alertmatrix I've heard are good --bbalerts (mixed iffyness).
I myself use alertmax which can be configured by domain..messaage contents, user/contact & type of communication (lacks bbm messaging alerts though).
berrybuzz iirc is the first to support bbm alerts.
Q10! <- Love the 9000!! It's everything I wanted (minus enough ON BOARD memory)!!
<-9700 ---! more memory! small screen&keypad :( ->