I love steel frames. I used to own Aluminum frames and the "road buzz" from the frame vibrating killed my hands (made em' numb no matter how much I moved em'.) Steel soaks up vibration and is tough. If it cracks it can be re-welded. (Steel is more prone to rusting than Aluminum - treat your frame with Frame Saver) Aluminum cannot be rewelded if broken. Carbon definitely cannot. Aluminum fatigues. Carbon fatigues (developing stress fractures.)Carbon fiber fails alot. I don't trust it. There is a whole website devoted to carbon fiber part and frame failures - (the name escapes me.)
No offense to those who ride carbon - I personally don't trust it.
Titanium is supposed to be the best - I've never ridden it but I'd love to.
Scandium (a blend of Titanium with other metals is used on bikes by Salsa, but they're quite expensive to start with $2000.00 at least.)
Trek 520, Jamis Aurora, Surly Long Haul Trucker, Surly Cross Check, Surly Pacer, Raleigh Clubman, etc. are all Steel bikes. I personally think if you can nab a Jamis Aurora 2009 for under $1000 go for it. I own one and like it alot. If you can get in on any of these for under $1000 it's a good deal for a steel bike.
"Things look different from the seat of a bike carrying a sleeping bag with a cold beer tucked inside." ~Jim Malusa
2009 Trek 520-Brooks B-17 Special in Antique Brown
2010 Surly Long Haul Trucker-Brooks B-17 Standard in Black
1983 Fuji Espree Single Speed-Brooks B17 British Racing Green