The article reviews recent progress in exploring effective materials for magnetocaloric effect (MCE), with a focus on LaFe13-xSi_x-based alloys that exhibit large entropy changes near room temperature. These alloys undergo a first-order magnetic transition, which is crucial for their MCE. The effects of magnetic rare-earth doping, interstitial atoms, and high pressure on the MCE are systematically studied. Special issues such as determining the MCE associated with first-order transitions, reducing magnetic and thermal hystereses, and key factors influencing magnetic exchange in these alloys are discussed. The applicability of these materials for magnetic refrigeration near ambient temperature is evaluated, and other materials with significant MCE are briefly reviewed. The study highlights the importance of understanding the thermodynamics of MCE, the role of first-order transitions, and the challenges in practical applications, such as reducing hysteresis losses.The article reviews recent progress in exploring effective materials for magnetocaloric effect (MCE), with a focus on LaFe13-xSi_x-based alloys that exhibit large entropy changes near room temperature. These alloys undergo a first-order magnetic transition, which is crucial for their MCE. The effects of magnetic rare-earth doping, interstitial atoms, and high pressure on the MCE are systematically studied. Special issues such as determining the MCE associated with first-order transitions, reducing magnetic and thermal hystereses, and key factors influencing magnetic exchange in these alloys are discussed. The applicability of these materials for magnetic refrigeration near ambient temperature is evaluated, and other materials with significant MCE are briefly reviewed. The study highlights the importance of understanding the thermodynamics of MCE, the role of first-order transitions, and the challenges in practical applications, such as reducing hysteresis losses.