The P35 is the best Intel chipset right now if you don't want SLI (dual video cards). I would 100% recommend the P35 chipset.
Though, it is true that not all processors will be compatible with certain chipsets, even if the socket is the same. The P35 is compatible with everything out there, and also will run Intel's upcoming 45nm processors.
I like Intel because they do offer much better performance than AMD. As far as 'bang for your buck', AMD does do better, but not by much. The E2180 I mentioned is *easy* to overclock high, and will out-perform all AMD stuff in that price range. It's when you start spending $300+ish that Intel suffers on 'bang for your buck'.
Here are my personal recommendations:
Motherboard:
Newegg.com - GIGABYTE GA-P35-DS3L LGA 775 Intel P35 ATX Intel Motherboard - Retail Newegg.com - ABIT IP35-E LGA 775 Intel P35 ATX Intel Motherboard - Retail
CPU:
Newegg.com - Intel Dual-Core E2180 Allendale 2.0GHz 1MB L2 Cache LGA 775 Processor - Retail Newegg.com - Intel Core 2 Duo E6550 Conroe 2.33GHz 4M shared L2 Cache LGA 775 Processor - Retail Newegg.com - Intel Core 2 Duo E6750 Conroe 2.66GHz 4M shared L2 Cache LGA 775 Processor - Retail
RAM:
Newegg.com - G.SKILL 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail Newegg.com - Patriot Extreme Performance 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail (Best) Newegg.com - Crucial Ballistix 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
Also, feel free to check out b1gapl's
Recommended PC Components post. It has all the frequently recommended things around here, and everything I have recommended is also in his post.