I like the Solti performance, but the most accessible recording of the Mahler #1 that I have is the Jascha Horenstein performance with the London Symphony Orchestra, on Unicorn RHS 301. Solti captures the drive and the energy (as only Sir Georg can do), but Horenstein captures the lilting grace and humor and more of the subtlety, while still keeping this a brisk affair.
Mahler "Symphony No. 1" Solti/London SO (London CS 6401).
Those who are afraid to explore Mahler may want to start out with this one. I am not a big fan of Mahler, but I find this Symphony very approachable.
(Slipknot1, above)