I've been enjoying the Ultimates. I enjoy the grittiness and more adult tone, with violence and relationships. The most recent twelve-part series was actually quite gripping, even with its often ludicrous plotting. I'll keep reading it.
The Ultimate Avengers 1 was a jumble of violence and rape (often as a clumsy character backstory for the women), and some very poor plotting and characterisation. Ultimate Avengers 2 worked well at times, but seemed a little adolescent next to the 'death of Spiderman' story. The Punisher was poorly used.
I've not got into Ultimate Spiderman, but Ultimate Spider-men has been very good so far. Well paced, smart, funny.