Well I think Hl2 is not that good well above average but still inferior to Half-Life. The episodes are better tough. The content is tighter(and shorter). Episode 1 is a fun ride and 2 is even better. Addicted to TF2 yet or got bored of it too?
And yes I really like HL1 better than HL2. The AI is HL2 just isnt interesting like it was in the 1st and other games like Far Cry or even Stalker all games that gave me more challenge and surprising NPC reactions.