Setting aside Tier 1 classes that can trivially pretend to be fighters (Druid comes to mind), you have three different and flavorful options.
Psychic Warrior, (Any from the tome of battle, but Swordsage tends to have the most flavour/skills), The Totemist (Incarnum), and the Factotum. Note that all of these classes (save the incarnum ones that aren't rated) are Tier 3, while fighters are tier... 5.
The psychic warrior does not need to invest all of their powers known into pure-combat powers, and consequently gains non-trivial utility choices that directly benefit out-of-combat situations. I've played a half-giant Psychic Warrior "named Gar" who had earth power and had tremendous fun out of combat with him due to his libertarian propensities. (He was quite prepared to discuss, calmly and quietly, why the guards wanted to confiscate his 20' deep crystal spear. Really weirded the GM out with that one). The earth power feat allowed for a remarkably nuanced "sonar ping" that came in handy when scouting. Quite a lot of fun, and the base model allowed for huge amounts of characterization and imaginative solutions to problems.
The Swordsage with a focus on dex/wis and 6+ skill points makes him excellent on the battlefield and excellent as a scout. While I've never played one, the swordsage is my choice if I ever have to play a fightery type and psionics are barred. Because the disciplines can key off skills, the focus of the class supports far more nuanced and effective skill use.
The Totemist ... as the guide says is a build-your-own monster. There are plenty of "non-combat" abilities that a totemist can get that (barring being talky) provides plenty of non-combat options.
The Factotum is a literal omni-skill, having every single skill as their class skill. With inspiration points (and font of inspiration taken 3 or 4 times) they can put up a remarkable simulacra of being a fighter for 3-4 rounds before they call it a bad hair day and go find a mirror somewhere. Outside of that, no other class even approximates their skills. Since they have ijiatsu focus as a class skill (as well as the dreaded craft:basketweaving), and can add their int to... basically everything (attacks, damage, basketweaving...) one way or another, this is the class chosen for maximum out-of-combat utility while probably being more effective than a bog-standard fighter. I'm playing one in a midnight game and enjoying it. The obscene hide checks make "normal" combats slightly redundant, however.