Core Switch Suggestions?

I'm looking to pick up a new core switch for my lab. My current switch, a Dell PowerConnect 6024, has been giving me lots of issues. I can't initiate a console session to it (I've tried EVERYTHING) and the SFP ports leave a lot to be desired in terms of compatibility with DACs and modules.

This said, I'd love it if you beautiful bastards could tap into all if that juicy knowledge and experience to make some recommendations to me as to what switch I might want to be looking into. Here are my criteria:

• <$300
• SFP+ (2-4 ports) (might be dreaming a little here for the price point)
• Managed
• Layer 2/3
• Brocade and Cisco DAC compatibility