I started reading Thunderbolts from #110, where Ellis' run began, I'm with you STL Thunderbolts is definitely a top read. Caged Angels is a stellar arc (#116 - #121).

Sadly though the same couldn't be said with the Secret Invasion tie ins (#122 - #125). Mediocre at best.

Luckily it's picked up with the current run with Diggle (#125 onwards). I'm especially looking forward to the new Thunderbolts team and the upcoming crossover with Deadpool.

Also want to mention that Thunderbolts has the best cover art (minus the Secret Invasion ones).