Two sci-fi shows I thought were great but somehow turned out terribly, terribly wrong

1) Heroes. My theory on why the show started going downhill in season two: The writers abused time travel. Now, no one stays dead, so nothing has any consequence or finality. Lame.

2) Smallville. This used to be my favorite show, but has become downright unwatchable this season. No Lex Luthor, no Lana Lang. No Smallville even.