To your left we have several brands of test kits. We receive good reviews and complaints on just about every brand, ranging from hard to use and inaccurate. So picking the best test kit is extremely hard. Lamotte, KZ,  Salifert & Elos are considered more toward the higher end spectrum. Seachem is a nice middle of the road range and RedSea & Industrial Dip is more for quick checks, lower end test kits.

RedSea

Salifert

Seachem

LaMotte

KZ - ZEO

Tropic Marin

Elos

Sera

Hanna Checkers