Well being new to the hobby myself I have only experience in two engines. My first was an Evolutions .46, it was gutless, but it had the training flywheel so that was probably why. It idled like a dream once you got to tuned. However, I question material qualities since after a couple months flying I put the same oil I used in my OS engine in it as after run and set it away for the winter, only to find the bearings rusted so badly the next year that it rattled and coughed and sounded awful. (I didn't know it was the bearing till I tore it down after that weekend flight.)

The OS I replaced it with is a .46FX and its a typical OS (Read more power than my trainer really needs!) I run circles around the flying field for 20 minutes at 1/4 to 1/3 throttle and when we land it it usually has 1/2 a tank of gas left. Best part, I put the plane away for over 2 years, with just some Marvel Mystery oil in it once a year or so. When I took the plane down to set up for another go at this hobby all I had to do was clean the motor and its smooth as silk!

My vote between these two is the OS, I've seen a couple Tiger engines (Cant recall if it was the TT or ST) and the owners were always very happy with them, but I have no first hand experience there.