She's different, which is nice.
Until now, House has picked fairly ordinary people... and the women were always attractive. He even commented that's why he chose Cameron, and for the others it didn't hurt.
Park is... different. She refuses to settle into as many social norms, that's one of House's mottos. Sure, some of it is she's strange enough to not be able, while in others she's specifically said "why should she." Also she decked her boss, something that I'm sure deep inside House respects even though he believes it was an ultimately stupid move.
Do I think she's awesome? No
Do I think she's an interesting character? Sure
Look at the entire cast except for Taub... they all started up as attractive and ordinary people with a character flaw buried underneath that House liked. Taub was the first difference as he was older.