The 135i is certainly worth considering. I had one before I got my E46 M3. It isn't as raw as the M3 (the E46 anyhow) but is tossable and tunable and has all the newest creature comforts (with the E46 M3 is now showing it's age in regards to).
With the 135 make sure you get the sports package version with the sport seats. But it was a great little car and I remember it fondly and occasionally miss it. Maybe because it was my first BMW. It also got pretty decent gas mileage but did have somewhat of a small gas tank which was a pain in the butt, but not a deal breaker.