I will echo Robert's words. "Best quality models" is a useless forum topic that appears on a monthly basis. An old company like Esci made the best M60A1/A3 tank kit, but most every other modern armor kit stunk. Tamiya makes the best HMMWV model but their M3 Grant/Lee tanks are old dogs.
The best way to ask the question is "Who makes the best ______ in 1/48 scale?"
Or "How is the 1/48 scale Revell F-14?"
Do not rely on the brand stated on the box. Many companies today rebox one another's kits. The "new" Revell of Germany T-72 is the old Dragon kit, which is also boxed by Zvezda. The "new" Revell of Germany M3 White Scout Car is a 40 year old Peerless Max kit that has been reboxed by Italeri, Testors, Zvezda and now Revell of Germany.
Revell merged with Monogram in the 1990s to become Revell-Monogram. Because of this, many of the older Monogram kits now show up in Revell boxes. Revell also took over Renwal kits in the 1980s so every once in a while an old Renwal kit shows up in a Revell box. Monogram took over Aurora kits in the late 70s. Even some old Monogram kits and old ex-Aurora kits have started showing up in Revell of Germany boxes (Skipjack nuclear sub for one).