AMD's Athlon and Turion series of processors have grown very popular in the recent past. Both Athlon and Turion are a series or category of processors. When comparing processors, it is more relevant to compare specific processors rather than processor families. For example, see Comparison of AMD Athlon 64 X2 Dual-core TK-57 with AMD Turion 64 X2 Dual-core Mobile TL-60. Other processors can be compared at the Compare Processors page on Diffen.
edit Athlon vs Turion power consumption
Turion 64 has a lower power consumption than Athlon 64. The Athlon processor family was originally designed for desktops and Turion for laptops, which is why the Turion family is more energy efficient. However, both families were later used for both desktops and laptops.
edit Price comparison
Prices for Athlon vs Turion processors vary based on the specifications,like processor family, CPU speed etc. Prices for a few AMD processors are available on Amazon.com: