Really, most of the trouble with the Ranger comes from lack of flash, or as I like to call it, "coolness factor"
Utility wise the ranger has:
1. Fighter BAB and d10 hit die
2. Two good saves
3. Decent skill points and good list
4. Limited but useful spells.
I would argue that a ranger can replace a fighter. The fighter's feats are impressive, and ranger will never be quite as strong, but the saves and skills can help, especially when you are on either side of an ambush. Later, spells like Entangle, Protection from Elements, and Polymorph Self are helpful in combat.
In a dungeon, one of the better roles for a ranger is 2nd scout. Lone rogues have a habit of getting into lots of trouble, and guys in plate mail are SLOW.
Thoughts on improving the ranger:
1. Custom Spells. Paladins get Holy Sword, etc., after all. This would go a long way toword increasing coolness factor.
2. Virtual feat packages given out over time, e.g.:
1st Ambidex
3rd TWF
6th Improved TWF (yes, this is early for it. Thus, very high coolness

)
OR
1st Point Blank Shot
3rd Precise Shot
6th Rapid Shot
This one seems a bit slow, but I like levels 1,3,6 for this, as those are relatively empty levels for the class. The argument could be made for 1,2,3 or 1,2,6.
Of course, I have a vested interest in the ranger, as I currently play a Rgr9/Ftr2 (fighter for the feats needed to maintain some of the flavor of my profoundly illegal access to Weapon Mastery in 2E. I have since reformed my munchkinnish ways

)
Final Note: Like the Paladin and Monk, the ranger really shines with a good set of ability scores. Str, Dex, and Con are of course important to any fighter-type, but Int and Wis appeal to the ranger far more than they do to a fighter. I would hazard that a ranger can make much better use of lucky rolls or high point buy than a fighter. for 32 points, you can go with five 14s and a 10 in Cha (boring, but a useful example).