Feel the Fire is GOAT, virtually flawless. Taking Over is kind of exactly the middle-point between its adjacent albums; the production is worse than FtF but not quite as tinny as UTI, the leftovers from FtF are pretty good but still leftovers, the newer songs are a bit chuggy but never go full Anthrax, etc. Overall pretty good still. The Years of Decay has grown on me a lot once I dealt with all the Metallica-wannabe parts, some parts are almost tech-thrash with how tricky they are yet never losing the aggression, and some of the diversions like Skullkrusher are among their best.
Overall Overkill is a pretty inconsistent band for me though, each stylistic period having its own highs and lows.